Help required with photo coupler selection.

Thread Starter

peterdbennett

Joined Jan 28, 2019
3
Hi I have a circuit where I require an arduino to switch a photo coupler. The coupler is required to switch a circuit with max voltage 100v and 400mA DC can anyone suggest a component preferably in a 4dip through hole package please.
Thanks
P
 
Last edited:

MaxHeadRoom

Joined Jul 18, 2013
28,619
I would think that one of the small SSR's would be in the range, but not DIP.
If DC and can do without the isolation, a logic level Mosfet could do it.
Max..
 

Thread Starter

peterdbennett

Joined Jan 28, 2019
3
Thanks Max i checked out the assr but the turn on off time off the ssr is way to slow. I need something in the uS range. I'm generating a biphasic pulse with pws from 1 to 4ms.
 

djsfantasi

Joined Apr 11, 2010
9,156
Thanks I tried these in the past fried them
And was the problem with the part, the design or the designer?

If I use a component incorrectly, maybe without a current limiting resistor or too high an input voltage or current, I’d buck up and make it a learning experience. Not take the chance that I’ll make the same mistake on another part.

I’m not saying that this applies to you, but your facile comment “fried them” made me wonder if you knew why you fried them.
 

ci139

Joined Jul 11, 2016
1,898
... max voltage 100v and 400mA DC... please. Thanks
P
the 400mA seems a bit overquota for commonly used optically coupled phototransistors but https://eu.mouser.com/Semiconductors/Integrated-Circuits-ICs/Optocouplers-Photocouplers/_/N-abedt scroll filters right and range your If the Ic --or-- Io would be 1x to 4x greater incase of optocouplers

with conjunction of these you need to use a base shunt for faster turnoff ... or don't doubt to examine further the MOSFET IGBT drive design concepts

a slow turnoff means that your opto transits slowly through ohmic range towards the higher impedance -- so if it withstands 100V 400mA (which i doubt it does -- as for the collector voltage×current) then it will dissipate 40W needs a good heat-sink of the size and mass of your soldering iron and it still gets to 300°C and cooks your opto if it doesnot auto-unsolder and fall off the PCB first
 

SamR

Joined Mar 19, 2019
5,031
2 things here, optoisolation and switching. Maybe an optoisolator triggering a TIP (Darlington pair) Xstr or a MOSFET switch?
 
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