I can't get SCR's to work

"Jason S"

............ Phil

gate)

Here's an example test circuit - what you are doing seems to be correct though maybe the resistor value is incorrect. I don't have the data sheet for yours on hand, but the circuit referenced gives 270 Ohm as the resistor value. Have you tried one that low?

Ken

1) is the SCR and LED connected the right way around?

Try this circuit below it should show you if the SCR is working. Use a normally open push button switch to trigger the SCR and once triggered the

+12V -------------------- | | | | | 12V 6W globe | | | | anode / ----- \ R \ / / - | gate / | cathode | _|_ / |

- ------- -------- | switch

R = 270 ohm

If this circuit works then the problem with your LED circuit is either component polarity or insufficient current draw.

thanks guys. its fine now.

Jason.

(snip)

Fess up, wot'd you change?

well i didn't realise the SCR's anode, cathode and gate are in different order compared to that of a transistor. I always assumed the gate was the middle pin. Ha ha. I laughed it off, but I'm relieved now. I've never worked with SCR's before.... First time for everything!! ;-)

"Jason S"

........... Phil

Tranny with an anode, cathode and gate?? :-)

You'll find that transistors have their pins in different orders as well. Some will be Collector, Emitter, Base whilst others are Collector, Base, Emitter... and so on..

Sounds like you could make use of a transistor reference guide that has the pinouts included.....

u could say that. Jason.