Hi all,
I would like to put together a circuit that controls a electrically operated switch and can measure the amount of voltage running through it.
The volatge/amps would be quite high (inductive / 30-45 VDC / 30 Amps) so I was thinking of using an optocoupler.
My knowledge of electronics is not great but I previously setup a mosfet controlled circuit that operated based on the temperature, and it has been working good until now.
I don't know much about optocouplers so could you please help with the following:
Is an optocoupler the correct way to go? do they handle high loads or are they used in combination with relays/mosfets?
If yes, can anyone recommend a specific optoisolator that can be controlled from an arduino and will switch an inductive load of 30-45 VDC / 10-30 Amps for continued usage of about 30 mins?
How do you work out if an optocoupler specs are sufficient from the datasheet? (There are many and I don't understand them all)
How would you measure the voltage running through an optocoupler since it is isolated from the microcontroller side?
Opto couplers are small ICs designed to isolate two parts of a circuit. Eg, a 12v signal from a car into the 5v circuit of an Arduino. They are low current devices.
What you are possibly thinking of is a solid state relay that uses a LED input to optically isolate the high voltage/current output.
These are normally normally used in AC but can also be used in DC but check the specifications.
list your circuit, there may be a very simple place to tie in to measure.
also, why do you want to control the current ?
it seems your request is at the end of a lot of 'figuring' that may have bypassed very simple solutions.
AC current is very easy to measure with a CT or current transformer.
typically, for DC you use a shunt resistor of some very low value and measure the voltage drop across, but without details of what you have and what you need, all our guessing is pointless.