Hello

I need to switch 60V DC with a opto-coupler.

Actually this opto is used to switch the gate of a P channel MOSFET wired as a high side switch. The opto switches the resistor divider from 60VDC to gate.

My problem is Can I use a 80Volts opto to switch 60vdc? I plan to use quad optocoupler package with VCE of 80Volts.

Do we need to go for 100V or above?

My purpose is to isolate the +5V side and devices from this 60Volts area

thanks

Roy

 

Thanks a lot for the information.
I need some more suggestions from here.
I am basically a MCU programmer but new to electronics design. I am learning it for this project using Proteus VSM.

I need to measure current 0 to 500ma with .1mA resolution.
On over current (exceeds 500mA) I need to cut off also. from MCU. The software part I believe I can manage!

For the current sensing and amplifying I have drawn a design. But I need suggessions on the factors I over looked in this .

I have attached VSM print with full current and minimum current levels . Please advice weather it will work as I planned .I have written details in schematics also

Please

Roy

 

If you want to protect the OP place a zener diode in parallel to R10 so that V across it will never exceed the zener value.

Thanks, Will Do it.Hope it wont create any effect on current or impedance.

I would have connected the opto diode directly to the MCU via a 330 ohms resistor, saving the Q2.

But my setup has this sort of arrangement for 12 channels. So MCU Sourcing this much current for 12 opto LEDS seems not ok for me. What you say?

Well done It should work.

frankly ,that gave me lot of confidence.

Thanks lot

 

After the opamp stages I plan to use a low pass filter. 2 ploe sallen key using the same opamp. What should be the cut off frequency? What will be a good choice or my design?

Also can i use this filter after the multiplexer? Or else just after the opmap stages? In that case i have to construct 12 filters?
thanks

Roy Thomas