Electronic Controller for The TRIAC ( BTA100-800B )

[sam_sam_sam]

I bought one of these units

Here is the pictures of the two boards that make up this controller
If I change the resistor to the optic sensor ( on the LED input side ) could I get better control of this triac

The ( “0” ) setting is zero power to the output side of this controller

The problem I have with this version of it is that most of your control is from a setting of 30 to 35 on the controller display which translate to about 1 to 15 amps

Or a little over 2 amps per step

I would like to change this to 1 amp per step

From this I estimate that this transformer at full 120 volt without any controller is probably about 50 amps or so

Because I have tripped a 20 amp break a few times already

In my shed where I going to be using it I am probably going to put a 50 amp break in it to be able to use it a lot higher amps than what the controller that was on it was doing

But we are only talking about 250 to 500 milseconds ON time or maybe less time than that

This is on this battery spot welder that the controller went bad that I am trying modify to use replaceable controller parts with

Here is a picture of both boards

[redwire]

Re: Electronic Controller for The TRIAC ( BTA100-800B )

I would try the unit with a light bulb/heater load and multimeter, to see if it is more linear with a resistive load. The inductive-load transformer might be confusing the unit.

You are thinking of driving the opto with less current, but that doesn't drive the triac less, as in a linear control. A triac is either on or off, you just need to control when in time (on a sine-wave) it turns on, to modulate the power.

Looking at the boards, I'm guessing it has a single chip MCU and which tries to phase-control a triac. Can you set it for 50/60Hz? I'm not sure how good this design is, they say "non-linear" voltage control for the "10000W scr voltage regulator" it's called. The zero-cross detection, or triac inductive-load triggering may be malfunctioning, or it's just crappy chinese firmware.

For spot-welding, most people are using a 555 timer and foot switch to pulse a SSR or scr/triac's like you have on the power board. You could just ditch the MCU board. The 4-pin cable has (+5V, zero-cross, GND, SCR opto drive)

[sam_sam_sam]

Re: Electronic Controller for The TRIAC ( BTA100-800B )

For spot-welding, most people are using a 555 timer and foot switch to pulse a SSR or scr/triac's like you have on the power board. You could just ditch the MCU board.

I would like to do that but here is my problem I have to do milliseconds
I have a timer that will do milliseconds

The 4-pin cable has (+5V, zero-cross, GND, SCR opto drive)

What kind of zero controller could I use that would work for an inductive load (transformer)

Do any idea or point me in the right direction

Thanks

[sam_sam_sam]

Re: Electronic Controller for The TRIAC ( BTA100-800B )

A triac is either on or off, you just need to control when in time

I understand that a triac is either on or off

(on a sine-wave) it turns on, to modulate the power

I have tried to find a circuit on google to do this with no luck or I just not using the right terminology

When googling for the right circuit to build for this project what terminology do I need to use

[redwire]

Re: Electronic Controller for The TRIAC ( BTA100-800B )

I'm not sure what you are controlling power, it is a spot welding transformer?

These are energized with full mains just for a little blip, for 10-100's milliseconds kind of thing. So a triac switches full power off/on/off to the transformer for many powerline cycles.

Instead, if the triac is always turned on only for a part of a mains power cycle (repeatedly), let's say 90 degrees, then you get 1/2 power which averages to 1/2 the voltage.
This is like a lamp dimmer, or how your "10000W scr voltage regulator" is. It dials down steady power flow compared to a one time blip.

555 timer to make the pulse. Fancier builds use an Arduino spot welder.
http://www.instructables.com/howto/spot+welder
https://hackaday.com/2014/09/21/a-pr...ve-transformer

[budm]

Re: Electronic Controller for The TRIAC ( BTA100-800B )

"This is on this battery spot welder that the controller went bad that I am trying modify to use replaceable controller parts with"
Can we see what the old controller looks like and how it is being used?

[sam_sam_sam]

Re: Electronic Controller for The TRIAC ( BTA100-800B )

Can we see what the old controller looks like and how it is being used?

I will tried to post the picture of both sides of the board tomorrow

[budm]

Re: Electronic Controller for The TRIAC ( BTA100-800B )

Get the Make and model too.