# Developing an AC circuit using DC

I have a project that will eventually monitor and control an AC circuit:

However, I do not have an 8VAC power source to develop with apart from the one in use for the doorbell (or even a spare AC chime for that matter). I do have a 5VDC and lots of DC components (LEDs for example).

Are there any tips on how I can develop this circuit using a 5VDC power source and say an LED or are the concepts just too dissimilar to even bother?

Need some details - what are you going to measure and what are you going to control ?

For example if your “ control “ of the AC device is to just switch it on/off ( using say a relay) or to control the power to it by phase angle control ( say thyristor ), then in one case you don’t need the ac to develop it , in the other you do

It's a simple circuit for a doorbell that can be enabled and disabled, as well as generate a signal when the button is pressed. There's more details including a circuit diagram via the forum link in my OP.

The bit that I'm concerned about is the optocoupler and associated diode and capacitors. At best they don't matter but at worst they'll do something bad

All you need is to have two sets of three diodes soldered such that you have 3 in series facing one way and the other 3 soldered in series and soldered facing the other direction across the first set . Wire this diode pack in series with the bell. - so the bell will still work and pass an AC current . The diodes will drop
About 1.8 volts - so if you connect an led with a small resistor (56 ohm) across the diode pack it will light when the bell rings - put that in a tube with some form of light sensor and you have an isolated digital device to act as an input to the arduino. Or alternatively wire your opto coupler across the pack with the resistor .

Hope this makes sense - written on my dog and bone .

It makes sense! But I'm afraid I'm not being clear.

I already have a circuit designed, and it's the one I'd like to develop. However I dont have access to an AC power source to test it with.

My question is whether I can adequately test the circuit with a DC power source instead, and if so whether there's anything specific I have to do to "emulate" the AC current.

I already have a circuit designed, and it's the one I'd like to develop.

So before we can answer your question you will have to post the schematic. It could be that something in the circuit needs AC, like a triac or SCR.