DIY welding inverter arduino. DIY welding inverter. Types of timers for spot welding

2017-08-22 at 01:31

It became necessary to weld 18650 batteries. Why weld and not solder? Because soldering is not safe for batteries. Soldering can damage the plastic insulator and cause a short circuit. Welding, on the other hand, achieves a high temperature for a very short period of time, which is simply not enough to heat the battery.

Internet search ready-made solutions led me to very expensive devices, and only with delivery from China. Therefore, it was a pleasure to make the decision to assemble it yourself. Moreover, the "factory" devices spot welding use some basic homemade components, namely a microwave transformer. Yes, yes, it is he who will be useful to us in the first place.

List of required components welding machine batteries.
1. Microwave oven transformer.
2. Arduino board (UNO, nano, micro, etc.).
3. 5 keys - 4 for setting and 1 for welding.
4. Indicator 2402, or 1602, or some other 02.
5.3 meters of wire PUGV 1x25.
6.1 meter of wire PGV 1x25. (so as not to confuse you)
7. 4 tinned copper cable lugs type KBT25-10.
8. 2 tinned copper cable lugs type SC70.
9. Heat shrink with a diameter of 25 mm - 1 meter.
10. Slightly shrink 12 mm.
11. Heat shrinkage 8 mm - 3 meters.
12. Circuit board- 1 PC.
13. Resistor 820 Ohm 1 W - 1 pc.
14. Resistor 360 Ohm 1 W - 2 pcs.
15. Resistor 12 Ohm 2 W - 1 pc.
16. Resistor 10 kOhm - 5 pcs.
17. Capacitor 0.1 μF 600 V - 1 pc.
18. Triac BTA41-600 - 1 pc.
19. Optical isolation MOC3062 - 1 pc.
20. Two-pin screw terminal - 2 pcs.
Everything seems to be in terms of components.

Transformer rework process.
We remove the secondary winding. It will consist of a thinner wire, and the number of its turns will be large. I recommend cutting off one side. After being cut off, we knock out in turn from each part. The process is not fast. It will also be necessary to knock out the separating winding plates, which are glued.

After that, as we have a transformer left with one primary winding, we prepare a wire for winding a new secondary winding. To do this, we take 3 meters of wire PGV 1x25 with a cross section. We completely remove the insulation from the entire wire. We put heat-shrinkable insulation on the wire. Heat to seat. In the absence of an industrial hair dryer, I made the shrinkage over the candle flame. Replacing the insulation is necessary so that the wire can completely fit into the place for the winding. After all, the native insulation is quite thick.

After we have seated the new insulation, we cut the wire into 3 equal parts. We put it together and wind two turns with such an assembly. I needed help with this. But everything worked out. Then we align the wires with each other, clean and put on 2 ends of 2 copper cable lugs with a cross section of 70. I could not find copper lugs, I took tinned copper ones. By the way, the wires intermeddle, you just have to try. Once put on, we take a crimper for crimping such tips and crimp. These crimpers are also hydraulic. It turns out much better than knocking down with a hammer or something else.

After that, I took a heat shrink with a diameter of 25 mm and threw it over the tip and the entire part of the wire extending from the transformer.

The transformer is ready.

Preparation of welded wires.
In order to make it more convenient to cook, I decided to make separate wires. Chose, again, ultra-flexible power wire PUGV 1х25 red. The cost, by the way, did not differ from other colors. I took one meter of such a wire. I also took 4 more tinned copper lugs 25-10. I divided the wire in half and got two pieces of 50 cm.On each side I stripped the wire 2 cm each and put on the heat shrinkage in advance. Now I put on tinned copper lugs and crimped it with the same crimper. I set the heat shrink, and that's it, the wires are ready.
Now we need to think about what we will cook. I liked the tip for a soldering iron with a diameter of 5 mm on the local radio market. I took two. Now it was necessary to think about where and how to attach them. And then I remembered that in the store where I took the wires, I saw zero tires, just with many holes with a diameter of 5 mm. He also took two pieces. In the photo you will see how I screwed them on.

Installation of electronic components.
To build a welding machine, I decided to use an Arduino board. I wanted to be able to adjust both the cooking time and the number of such welding. For this I used a display of 24 characters by 2 lines. Although you can use any, the main thing in the sketch is to configure everything. But more about the program later. So, the main component in the circuit is a triac BTA41-600. Here are the diagrams of the battery welder.

Key block diagram.

Diagram of connecting the display to the Arduino.

That's how I soldered it all. I didn't bother with the board, I didn't want to waste time drawing and etching. Found a suitable case and adjusted everything with hot melt glue.

Here is a photo of the process of finishing the program.

Here's how to temporarily make the welding key. In the future, I want to find a ready-made foot key so that my hands are not occupied.

With electronics sorted out. Now let's talk about the program.

Welding machine microcontroller program.
The program was based on some part of this article https://mysku.ru/blog/aliexpress/37304.html. True, it had to be changed significantly. There was no encoder. It was necessary to add the number of penetrations. Make it so that the settings can be made with four buttons. Well, so that the welding itself is carried out using a foot switch, or some other one, without timers.

#include

int bta = 13; // The output is connected to the triac
int svarka = 9; // Display the weld key
int secplus = 10; // Display the key to increase the cooking time
int secminus = 11; // Display the key to decrease the cooking time
int razplus = 12; // Display of the key for increasing the number of penetrations
int razminus = 8; // Display the key to decrease the number of penetrations

int lastReportedPos = 1;
int lastReportedPos2 = 1;
volatile int sec = 40;
volatile int raz = 0;

LiquidCrystal lcd (7, 6, 5, 4, 3, 2);

pinMode (svarka, INPUT);
pinMode (secplus, INPUT);
pinMode (secminus, INPUT);
pinMode (razplus, INPUT);
pinMode (razminus, INPUT);
pinMode (bta, OUTPUT);

lcd.begin (24, 2); // Indicate which indicator is installed
lcd.setCursor (6, 0); // Set the cursor to the beginning of line 1

lcd.setCursor (6, 1); // Set the cursor to the beginning of line 2

delay (3000);
lcd.clear ();
lcd.setCursor (0, 0);
lcd.print ("Delay: Milliseconds");
lcd.setCursor (0, 1);
lcd.print ("Repeat: times");
}

for (int i = 1; i<= raz; i++) {
digitalWrite (bta, HIGH);
delay (sec);
digitalWrite (bta, LOW);
delay (sec);
}
delay (1000);

void loop () (
if (sec<= 9) {
sec = 10;
lastReportedPos = 11;
}

if (sec> = 201) (
sec = 200;
lastReportedPos = 199;
}
else
(if (lastReportedPos! = sec) (
lcd.setCursor (7, 0);
lcd.print ("");
lcd.setCursor (7, 0);
lcd.print (sec);
lastReportedPos = sec;
}
}

if (raz<= 0) {
raz = 1;
lastReportedPos2 = 2;
}

if (raz> = 11) (
raz = 10;
lastReportedPos2 = 9;
}
else
(if (lastReportedPos2! = raz) (
lcd.setCursor (8, 1);
lcd.print ("");
lcd.setCursor (8, 1);
lcd.print (raz);
lastReportedPos2 = raz;
}
}

if (digitalRead (secplus) == HIGH) (
sec + = 1;
delay (250);
}

if (digitalRead (secminus) == HIGH) (
sec - = 1;
delay (250);
}

if (digitalRead (razplus) == HIGH) (
raz + = 1;
delay (250);
}

if (digitalRead (razminus) == HIGH) (
raz - = 1;
delay (250);
}

if (digitalRead (svarka) == HIGH) (
fire ();
}

As I said. The program is designed to work on indicator 2402.

If you have a 1602 display, replace these lines with the following:

lcd.begin (12, 2); // Indicate which indicator is installed
lcd.setCursor (2, 0); // Set the cursor to the beginning of line 1
lcd.print ("Svarka v.1.0"); // Display the text
lcd.setCursor (2, 1); // Set the cursor to the beginning of line 2
lcd.print ("site"); // Display the text
delay (3000);
lcd.clear ();
lcd.setCursor (0, 0);
lcd.print ("Delay: Ms");
lcd.setCursor (0, 1);
lcd.print ("Repeat: times");

lcd.setCursor (7, 0);
lcd.print ("");
lcd.setCursor (7, 0);
lcd.print (sec);
lastReportedPos = sec;

lcd.setCursor (8, 1);
lcd.print ("");
lcd.setCursor (8, 1);
lcd.print (raz);
lastReportedPos2 = raz;

Everything is simple in the program. Empirically, we set ourselves the cooking time and the amount of cooking. Maybe 1 time is enough for you. I just feel that if you cook it twice, it turns out much better. But with you it may be different.

Here's how it worked out for me. First, I checked everything on a regular light bulb. Then I went to the garage (just in case).

Using a microcontroller in such tasks may seem too complicated and unnecessary to someone. A car battery may be sufficient for another person. But after all, it is interesting for a home-builder to make homemade products with the help of their own home-made products!

Incandescent lamp circuit test.

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Here is a diagram of a welding inverter, which you can assemble with your own hands. The maximum current consumption is 32 amperes, 220 volts. The welding current is about 250 amperes, which makes it possible to cook without problems with a 5-wire electrode, the arc length is 1 cm, passing more than 1 cm into low-temperature plasma. The efficiency of the source is at the level of the store, and maybe better (I mean inverter).

Figure 1 shows a diagram of a welding power supply.

Fig. 1 Schematic diagram of the power supply

The transformer is wound on a Sh7x7 or 8x8 ferrite
The primary device has 100 turns of 0.3mm PEV wire
Secondary 2 has 15 turns of PEV wire 1mm
Secondary 3 has 15 turns of PEV 0.2mm
Secondary 4 and 5 with 20 turns of wire PEV 0.35mm
All windings must be wound across the entire width of the frame, this gives a noticeably more stable voltage.

Fig. 2 Schematic diagram of a welding inverter

Figure 2 shows a diagram of a welder. The frequency is 41 kHz, but you can try 55 kHz. The 55kHz transformer is then 9 turns by 3 turns, to increase the PV of the transformer.

41kHz transformer - two sets Ш20х28 2000nm, gap 0.05mm, newspaper gasket, 12vit x 4vit, 10kv mm x 30 sq mm, copper tape (tin) in paper. The transformer windings are made of copper sheet 0.25 mm thick and 40 mm wide wrapped for insulation in paper from the cash register. The secondary is made of three layers of tin (sandwich) separated by fluoroplastic tape, for isolation between themselves, for better conductivity of high-frequency currents, the contact ends of the secondary at the output of the transformer are soldered together.

The L2 choke is wound on a Ш20х28 core, ferrite 2000nm, 5 turns, 25 sq. Mm, a gap of 0.15 - 0.5mm (two layers of paper from the printer). Current transformer - current sensor two rings K30x18x7 primary wire threaded through the ring, secondary 85 turns wire 0.5mm thick.

Assembly of welding

Transformer winding

The winding of the transformer must be done using copper sheet 0.3mm thick and 40mm wide, it must be wrapped with 0.05mm thick thermal paper from the cash register, this paper is strong and does not tear as usual when winding a transformer.

You tell me, why not wind it with an ordinary thick wire, but not because this transformer operates on high-frequency currents and these currents are displaced onto the surface of the conductor and does not use the middle of the thick wire, which leads to heating, this phenomenon is called Skin effect!

And you have to fight with it, you just need to make a conductor with a large surface, this thin copper sheet has this and it has a large surface through which the current flows, and the secondary winding should consist of a sandwich of three copper tapes separated by a fluoroplastic film, it is thinner and all these are wrapped layers into thermal paper. This paper has the property of darkening when heated, we don’t need it and it’s bad, from this, let the main thing remain that does not break.

You can wind the windings with a PEV wire with a cross-section of 0.5 ... 0.7 mm, consisting of several tens of cores, but this is worse, since the wires are round and dock with each other with air gaps, which slow down heat transfer and have a smaller total cross-sectional area of ​​wires combined in comparison with tin by 30 % that can fit into the windows of the ferrite core.

It is not the ferrite that heats up at the transformer, but the winding, so you need to follow these recommendations.

The transformer and the entire structure must be blown inside the case by a 220 volt 0.13 ampere or more fan.

Design

To cool all powerful components, it is good to use heatsinks with fans from old Pentium 4 and Athlon 64 computers. I got these heatsinks from a computer store doing upgrades, for only $ 3 ... 4 apiece.

The power oblique bridge must be done on two such radiators, the upper part of the bridge on one, the lower part on the other. Screw the bridge diodes HFA30 and HFA25 onto these radiators through a mica gasket. IRG4PC50W must be screwed without mica through KTP8 heat-conducting paste.

The terminals of the diodes and transistors must be screwed to meet each other on both heatsinks, and between the terminals and the two heatsinks, insert a board that connects the 300 volt power supply circuit with the bridge parts.

The diagram does not indicate it is necessary to solder 12 ... 14 pieces of capacitors of 0.15mk 630 volts to this board in the 300V power supply. This is necessary so that the transformer surges go into the power circuit, eliminating the resonant current surges of the power switches from the transformer.

The rest of the bridge is connected to each other by surface mounting with short conductors.

The diagram also shows snubbers, they have capacitors C15 C16, they must be of the K78-2 or SVV-81 brand. You cannot put any garbage there, since snubbers play an important role:
the first- they muffle the resonant emissions of the transformer
second- they significantly reduce the losses of IGBTs when turning off, since IGBTs open quickly, but close much slower and during closing, the capacitance C15 and C16 is charged through the VD32 VD31 diode longer than the closing time of the IGBT, that is, this snubber intercepts all the power on itself, preventing heat from escaping on the IGBT key three times than it would have been without it.
When the IGBT is fast open, then through the resistors R24 R25 the snubbers are smoothly discharged and the main power is allocated on these resistors.

Customization

Supply power to the PWM 15 volts and at least one fan to discharge the capacitance C6, which controls the response time of the relay.

Relay K1 is needed to close the resistor R11, after the capacitors C9 ... 12 are charged through the resistor R11, which reduces the current surge when the welding is switched on to the 220 volt network.

Without resistor R11 for a straight line, when turned on, a large BAC would have been obtained during charging a capacity of 3000mk 400V, for this this measure is needed.

Check the operation of the relay closing the resistor R11 2 ... 10 seconds after the power is applied to the PWM board.

Check the PWM board for the presence of square-wave pulses going to the HCPL3120 optocouplers after both relays K1 and K2 are triggered.

The pulse width should be the width relative to the zero pause 44% zero 66%

Check the drivers on optocouplers and amplifiers driving a square-wave signal with an amplitude of 15 volts, make sure that the voltage on the IGBT gates does not exceed 16 volts.

Apply 15 Volt power to the bridge to check its operation for the correct manufacture of the bridge.

In this case, the consumption current should not exceed 100mA at idle.

Verify the correct phrasing of the power transformer and current transformer windings using a two-beam oscilloscope.

One beam of the oscilloscope is on the primary, the second on the secondary, so that the phases of the pulses are the same, the difference is only in the voltage of the windings.

Apply power to the bridge from power capacitors C9 ... C12 through a 220volt 150..200W light bulb, having previously set the PWM frequency to 55kHz, connect the oscilloscope to the collector emitter of the lower IGBT transistor to look at the waveform so that there are no voltage surges above 330 volts as usual.

Start lowering the PWM clock frequency until a small bend appears on the lower key of the IGBT, which indicates transformer oversaturation, write down this frequency at which the bend occurred, divide it by 2 and add the result to the oversaturation frequency, for example, oversaturation of 30 kHz is divided by 2 = 15 and 30 + 15 = 45 , 45 this is the operating frequency of the transformer and PWM.

The current consumption of the bridge should be about 150mA and the lamp should barely glow, if it glows very brightly, this indicates a breakdown of the transformer windings or an incorrectly assembled bridge.

Connect at least 2 meters of welding wire to the output to create additional output inductance.

Apply power to the bridge already through the 2200 watt kettle, and set the current strength to the PWM at least R3 closer to the resistor R5 on the light bulb, close the welding output, check the voltage on the lower key of the bridge so that there is no more than 360 volts on the oscilloscope, while there should be no noise from the transformer. If there is one, make sure that the current transformer is correctly phased, pass the wire in the opposite direction through the ring.

If the noise remains, then you need to place the PWM board and the driver on the optocouplers away from the noise sources, mainly the power transformer and the L2 choke and the power conductors.

Even when assembling the bridge, the drivers must be installed next to the radiators of the bridge over the IGBT transistors and no closer to the resistors R24 R25 by 3 centimeters. The connections between the driver output and the IGBT gate should be short. The conductors from the PWM to the optocouplers should not run close to sources of interference and should be as short as possible.

All signal wires from the current transformer and going to the optocouplers from the PWM should be twisted to reduce the noise level and should be as short as possible.

Then we begin to increase the welding current with the help of resistor R3 closer to the resistor R4, the welding output is closed on the key of the lower IGBT, the pulse width increases slightly, which indicates PWM operation. More current - more width, less current - less width.

There shouldn't be any noise, otherwise they will failIGBT.

Add current and listen, watch the oscilloscope for overvoltage of the lower key, so as not to exceed 500 volts, maximum 550 volts in the surge, but usually 340 volts.

To reach the current, where the width sharply becomes the maximum, it is said that the kettle cannot give the maximum current.

Everything, now we go straight without a kettle from minimum to maximum, watch the oscilloscope and listen so that it is quiet. Reach the maximum current, the width should increase, emissions are normal, not more than 340 volts usually.

Start cooking, at the beginning 10 seconds. We check the radiators, then 20 seconds, also cold and 1 minute the transformer is warm, burn 2 long electrodes 4mm bitter transformer

The radiators of the 150ebu02 diodes noticeably warmed up after three electrodes, it is already hard to cook, the person gets tired, although it is great to cook, the transformer is hot, and no one else is cooking. The fan, after 2 minutes, the transformer brings to a warm state and you can cook again until it drops.

Below you can download printed circuit boards in LAY format and other files

Evgeny Rodikov (evgen100777 [dog] rambler.ru). If you have any questions when assembling the welder, write to E-Mail.

List of radioelements

Designation	Type of	Denomination	Quantity	Note	Shop	My notebook
	Power Supply
	Linear regulator	LM78L15	2			Into notepad
	AC / DC converter	TOP224Y	1			Into notepad
	Voltage reference IC	TL431	1			Into notepad
	Rectifier diode	BYV26C	1			Into notepad
	Rectifier diode	HER307	2			Into notepad
	Rectifier diode	1N4148	1			Into notepad
	Schottky diode	MBR20100CT	1			Into notepad
	Protective diode	P6KE200A	1			Into notepad
	Diode bridge	KBPC3510	1			Into notepad
	Optocoupler	PC817	1			Into notepad
C1, C2		10mkF 450V	2			Into notepad
	Electrolytic capacitor	100μF 100V	2			Into notepad
	Electrolytic capacitor	470uF 400V	6			Into notepad
	Electrolytic capacitor	50μF 25V	1			Into notepad
C4, C6, C8	Capacitor	0.1μF	3			Into notepad
C5	Capacitor	1nF 1000V	1			Into notepad
C7	Electrolytic capacitor	1000uF 25V	1			Into notepad
	Capacitor	510 pF	2			Into notepad
C13, C14	Electrolytic capacitor	10 μF	2			Into notepad
VDS1	Diode bridge	600V 2A	1			Into notepad
NTC1	Thermistor	10 ohm	1			Into notepad
R1	Resistor	47 k Ohm	1			Into notepad
R2	Resistor	510 Ohm	1			Into notepad
R3	Resistor	200 ohm	1			Into notepad
R4	Resistor	10 kΩ	1			Into notepad
	Resistor	6.2 Ohm	1			Into notepad
	Resistor	30ohm 5W	2			Into notepad
	Welding inverter
	PWM controller	UC3845	1			Into notepad
VT1	MOSFET transistor	IRF120	1			Into notepad
VD1	Rectifier diode	1N4148	1			Into notepad
VD2, VD3	Schottky diode	1N5819	2			Into notepad
VD4	Zener diode	1N4739A	1	9B		Into notepad
VD5-VD7	Rectifier diode	1N4007	3	To lower the voltage		Into notepad
VD8	Diode bridge	KBPC3510	2			Into notepad
C1	Capacitor	22 nF	1			Into notepad
C2, C4, C8	Capacitor	0.1 uF	3			Into notepad
C3	Capacitor	4.7 nF	1			Into notepad
C5	Capacitor	2.2 nF	1			Into notepad
C6	Electrolytic capacitor	22 uF	1			Into notepad
C7	Electrolytic capacitor	200 uF	1			Into notepad
C9-C12	Electrolytic capacitor	3000μF 400V	4			Into notepad
R1, R2	Resistor	33 k Ohm	2			Into notepad
R4	Resistor	510 Ohm	1			Into notepad
R5	Resistor	1.3 k Ohm	1			Into notepad
R7	Resistor	150 Ohm	1			Into notepad
R8	Resistor	1 Ohm 1 Watt	1			Into notepad
R9	Resistor	2 MOhm	1			Into notepad
R10	Resistor	1.5 k Ohm	1			Into notepad
R11	Resistor	25ohm 40Watt	1			Into notepad
R3	Trimmer resistor	2.2 k Ohm	1			Into notepad
	Trimmer resistor	10 kΩ	1			Into notepad
K1	Relay	12V 40A	1			Into notepad
K2	Relay	RES-49	1			Into notepad
Q6-Q11	IGBT transistor	IRG4PC50W	6

In some cases, instead of soldering, it is more profitable to use spot welding. For example, this method can be useful for repairing rechargeable batteries consisting of several batteries. Soldering causes the cells to heat up excessively, which can lead to cell failure. But spot welding does not heat up the elements so much, since it lasts for a relatively short time.

The Arduino Nano is used to optimize the whole process in the system. This is a control unit that allows you to effectively manage the power supply of the installation. Thus, each welding is optimal for a specific case, and energy is consumed as much as necessary, not more, and not less. The contact elements here are a copper wire, and the energy comes from a conventional car battery, or two, if a higher current is required.

The current project is almost perfect in terms of complexity / efficiency. The author of the project showed the main stages of creating a system, having laid out all the data on Instructables.

According to the author, a standard battery is sufficient for spot welding of two 0.15 mm thick nickel strips. For thicker strips of metal, two batteries are required in parallel. The pulse time of the welding machine is adjustable and ranges from 1 to 20 ms. This is sufficient for welding the nickel strips described above.

The author recommends making the payment to order from the manufacturer. The cost of ordering 10 such boards is about 20 euros.

Both hands will be engaged during welding. How do you manage the entire system? With a footswitch, of course. It's very simple.

And here is the result of the work:

Hey, brains! I present to your attention a spot welder based on the Arduino Nano microcontroller.

This machine can be used to weld plates or conductors, for example, to the terminals of an 18650 battery. For the project, we need a 7-12 V power supply (12 V recommended), as well as a 12 V car battery as a power source for the welding machine itself. Typically, a standard battery has a capacity of 45 A / h, which is sufficient for welding 0.15 mm thick nickel plates. To weld thicker nickel plates, you will need a larger battery or two connected in parallel.

The welding machine generates a double pulse, where the value of the first is 1/8 of the second in duration.
The duration of the second pulse is adjusted using a potentiometer and displayed on the screen in milliseconds, so it is very convenient to adjust the duration of this pulse. The range of its adjustment is from 1 to 20 ms.

Watch the video for a detailed description of the device creation process.

Step 1: Making the PCB

You can use the Eagle files to make a printed circuit board, which are available at the following.

The easiest way is to order boards from PCB manufacturers. For example, at pcbway.com. Here you can buy 10 boards for about 20 €.

But if you are used to doing everything yourself, then use the supplied diagrams and files to make a prototype of the board.

Step 2: Install components on boards and solder wires

The process of installing and soldering components is fairly standard and simple. Install small components first, then larger ones.
The tips of the welding electrode are made of 10 square millimeter solid copper wire. For cables, use 16 square millimeter flexible copper wires.

Step 3: footswitch

You need a foot switch to operate the welding machine as both hands are used to hold the tips of the welding electrode in place.

For this purpose, I took a wooden box into which I installed the above switch.

The timer of the time relay is a device with which you can adjust the time of exposure to current, impulse. The timer of the time relay for spot welding measures the duration of the effect of the welding current on the connected parts, the frequency of its occurrence. This device is used to automate welding processes, weld production, in order to create a variety of sheet metal structures. It controls the electrical load in accordance with a given program. A time relay is programmed for contact welding in strict accordance with the instructions. This process consists in setting the time intervals between certain actions, as well as the duration of the welding current.

Principle of operation

This time relay for spot welding will be able to turn on and off the device in a predetermined mode at a certain frequency on an ongoing basis. In simpler terms, it carries out the closing and opening of contacts. The rotation sensor is used to set the time intervals in minutes and seconds after the expiration of which it is necessary to enable or disable welding.

The display serves to display information about the current switch-on time, the period of exposure to the metal of the welding machine, the number of minutes and seconds before switching on or off.

Types of timers for spot welding

Timers with digital or analogue programming can be found on the market. The relays used are of different types, but the most common and inexpensive are electronic devices. Their principle of operation is based on a special program that is written on a microcontroller. It can be used to adjust the delay or turn-on time.

Time relays are currently available for purchase:

• with shutdown delay;
• delayed to turn on;
• adjusted for the set time after energizing;
• set for the set time after the impulse has been given;
• clock generator.

Time relay accessory

To create a timer relay for spot welding, you will need the following parts:

• Arduino Uno board for programming;
• Prototyping board or Sensor shield - provides easy connection of installed sensors to the board;
• female-to-female wires;
• a display that can display at least two lines with 16 characters in a row;
• relay that switches the load;
• a steering angle sensor equipped with a button;
• a power supply unit for supplying the device with electric current (during testing, it can be powered via a USB cable).

Features of creating a timer relay timer for spot welding on arduino board

For its manufacture, you must clearly follow the scheme.

At the same time, it would be better to replace the frequently used arduino uno board with the arduino pro mini, since it has a significantly smaller size, costs less and, at the same time, it is much easier to solder the wires.

After collecting all the components of the timer for resistance welding on the arduino, you need to solder the wires that connect the board to the rest of the elements of this device. All elements must be cleaned of plaque and rust. This will significantly increase the operating time of the relay timer.

You need to choose a suitable case and collect all the elements in it. It will provide the device with a decent appearance, protection from accidental shocks and mechanical stress.

At the end, it is necessary to install the switch. It will be needed if the owner of the welding decides to leave it unattended for a long time in order to prevent fire, damage to property in case of emergencies. With its help, leaving the room, any user can easily turn off the device.

"Note!

The 561 resistance welding timer is a more advanced device, as it is created on a new modern microcontroller. It allows you to more accurately measure the time, set the frequency of turning on and off the device. "

The 555 resistance welding timer is not as perfect and has a limited functionality. But it is often used to create such devices, since it is cheaper.

To better understand how to create a welding machine, it is worth contacting the company's employees. In addition, we propose to consider the scheme for creating this device. It will help you understand the principle of operation of the device, what and where to solder.

Conclusion

The timer for spot welding on arduino is an accurate and high-quality device that, with proper use, will last for many years. It is a fairly simple device, so it can be easily mounted on any welding. In addition, the spot welding timer is easy to maintain. It works even in severe frost, it is practically not affected by negative manifestations of the natural environment.

You can assemble the device yourself or contact the professionals. The latter option is more preferable, since it is guaranteed to provide the final result. The company will test the elements of the device, identify problems, eliminate them, thus restoring its operability.