[review] optotriac

michal_w

New Member
Hello colleagues,
I need to make a circuit to turn on a load resistor and then turn off ( I have to measure voltage with and witout load).
I've attached my scheme which I want to use. The load resistor is R2. I want to connect R1 with microcontroller.
Is it correct?
 

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Hi,

Im not sure if those opto's you are talking about using here are made for continuous load handling like that. Some of them are made just for firing a regular triac. You might want to double check the specs.
 
So, what should I use? I want to turn on and turn off the load resistor when I want, not when it cross zero (like using thyrisotrs or triacs).
 
Hi again,

What kind of load are you trying to drive, it is just a resistor? What value?
 
The MOC3020 can only switch 100mA max. so the maximum V1 supply voltage you could use with a 100 ohm resistor would be 10V. If you want to switch more current than that you can go with a larger DC output solid-state relay.

Edit: The MOC3020 also has a triac output so it will switch at the zero crossing. If you want it to switch otherwise you will need a DC output solid-state relay.
 
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Only resistor 100 Ohm - 1 kOhm.

Hi again,

Is your source voltage really AC or could you use DC, and what level is it (volts)?
 
I have to measure the output voltage of a transformer with and without load resistance.
Voltage range is 10-15 V.
 
Hello,
thanks for your replies.
If I will use solid state relay is it possible to switch off the load resistor in any moment of the time (like in attached picture) ?
 

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Hello,
thanks for your replies.
If I will use solid state relay is it possible to switch off the load resistor in any moment of the time (like in attached picture) ?
As I stated in my previous post, you need to use a DC output type solid-state relay.
 
Ya but thats an AC wave form in his pic. I must be confused.
A DC output solid-state relay is usually bipolar so it will also control AC.
 
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