resistor power control circuit with push buttons

Hi to everyone and thanks for your time.

Since I am a newbie in the construction of electronic circuits using arduino uno, I would like your guidance in the project that I try to complete.

Specifically, I want to construct a resistor power control circuit (dimmer) for a resistance of 60 Ω , 1300W and 220V.

I want to control this circuit using 4 steps buttons (not a Potentiometer). One button will increase the supplied voltage in specific values (e.g. the first push/step will supply 50 V in the resistance, the second 100V etc). An another push button will make the reverse process, it will decrease the voltage in specific values (a first push will decrease the supply voltage from 100V to 50V, a second push will decrease from 50V to 0 V etc).

This circuit will trigger the gate of a TRIAC BTA25.

I would appreciate if you gave me your advice for both the code that I have to write down and the corresponding wiring that I have to create for making my circuit functional.

Thank you in advance!!

Your presentation is not concistent. second push will decrease from 50V to 100V etc). Decrease?
Applying the maximum 220 volt to 60 Ohm resistor will produce 13200 Watt, 10 times more. That does not look safe.

An Uno will not deliver that voltage. It delivers 0 or +5 volts. PWM can be used.

Specifically, I want to construct a resistor power control circuit (dimmer) for a resistance of 60 Ω , 1300W and 220V

What are you trying to “dim”? A light? A heater?

A heater is LOT easier to control than a light…

A TRIAC is either on or off so you can’t (directly) use it to adjust voltage. Light dimmers work by [u]“phase control”[/u], turning the power on for part of the cycle, adjusting the average voltage.

The Arduino MUST be electrically isolated from the power line voltage. There are special TRIAC-driver opto-isolators. You also need to isolate the phase detection, which can be done with an opto-isolator or with a transformer.

Once you get the power-side figured-out, controlling it with pushbuttons is pretty easy. Logically it’s just some [u]if-statements[/u]. And, you could test that with a regular little LED and PWM dimming. It’s always best to develop, test, and debug the “input” and “output” separately before putting it all together.

for a resistance of 60 Ω , 1300W and 220V.

220V across 60 Ohms is 807W.
Power = Voltage x Current
Power = Voltage2/R
Power = Current2 x R

Yes, 807 Watts.

Lots of good safety information. Why not use a solid state relay and PWM?


Thank you all for your reply.

To make it more clear, I am attaching a draft diagram of my project.

Thank you!

OPs pic.

Tom.. :slight_smile:

I'm looking for a circuit, let's call it Dimmer,to test the power of a watt resistor (approximately 220v 1600w)using Arduino.

But I wanted to do the adjustment not with a potentiometer but with a push button pressing 4 times.

That is, one press 400w, second press 800w, third press 1200w and fourth press 1600w.

A second push button to do the reverse job.

Each pushing it down from 1600w to 1200w, 800w & 400w.

With this circuit I will control the resistance of an ironing board to have the desired temperatures for different types of fabrics. Thank you in advance as well as any other friend who can help me

I suspect if you want to use an Arduino it would be simpler to use a temperature sensor and a relay to turn the power on an off.


Sorry your idea although looks good would not work very well. The temperature will change with the load as well as the watts. The previous suggestion to use a thermal measuring device and controlling it via Triac would work well with the arduino but you have to know what you are doing as a mistook with the mains can having them digging a hole to put your body in.
Good Luck & Have Fun!

Is this associated with this thread?

Tom... :slight_smile:



Keep the same project together and do NOT cross post.

Read THIS POST to help you get the best out of the forum.


I think you are going to need phase control of AC.

If you need to control temperature you would be better to use a temperature sensor as well.

Can you tell us your electronics, programming, arduino, hardware experience?

Thanks.. Tom.. :slight_smile: