P
panfilero
- Jan 1, 1970
- 0
I'm trying to design an SCR based overvoltage crowbar circuit for a 100V to 24V DC/DC converter...I'm having some trouble finding the right part, here's my specs
My max load current is 1A. I have a 3A fast acting fuse at my input to the DCDC. I want an SCR that can handle 4A long enough for my fuse to pop, I want this to happen if my output goes to 30V...
so, I went off to go look for such a part... seems straight forward enough... I found this
http://www.onsemi.com/pub_link/Collateral/MCR703A-D.PDF
but the part says 4Arms, 2.6Aavg.... I'm just working in DC so I imagine RMS is the way I want to go here....
I also don't get the spec on SCRs that's called Vt which is the voltage across the anode to cathode when it's on... and it's usually 1.5V or so... if you have 30V across it how is it's votlage 1.5V or am I reading this wrong?
my last question is, how much voltage is it safe to put at the gate to turn these things on... I've seen 0.8V on datasheets as turn on voltage... is it ok to give them 1,2, or 3 volts at their gate?
much thanks!
My max load current is 1A. I have a 3A fast acting fuse at my input to the DCDC. I want an SCR that can handle 4A long enough for my fuse to pop, I want this to happen if my output goes to 30V...
so, I went off to go look for such a part... seems straight forward enough... I found this
http://www.onsemi.com/pub_link/Collateral/MCR703A-D.PDF
but the part says 4Arms, 2.6Aavg.... I'm just working in DC so I imagine RMS is the way I want to go here....
I also don't get the spec on SCRs that's called Vt which is the voltage across the anode to cathode when it's on... and it's usually 1.5V or so... if you have 30V across it how is it's votlage 1.5V or am I reading this wrong?
my last question is, how much voltage is it safe to put at the gate to turn these things on... I've seen 0.8V on datasheets as turn on voltage... is it ok to give them 1,2, or 3 volts at their gate?
much thanks!