Electronics people, I have a problem needs solving...

[norty303]

I have some of DZ's new breakout boards, and I have some of Guido's scanfail boards.
Guido's boards use 5V at 0.5mA on the interlock loops, which is not enough current to operate the loop thru relay on DZ's board.
David is kindly looking at solutions for me, but I thought I could explore other avenues in the meantime.

What is the simplest way I could amplify the 5V interlock, to a more sensible current (20-40mA perhaps?)
I'm no electronics person, but I could knock up something reasonably simple I expect, with some guidance.

[norty303]

Is something like this on the right track?

http://www.farnell.com/datasheets/85185.pdf

[Badpip]

You are over complicating things.

A transistor and a resistor is all you need :-)

/Thomas

[norty303]

Could you explain further please?

[Diachi]

Or use a MOSFET and forget the resistor.

A transistor is an amplifier essentially. You attach the signal you have to the base of the transistor. When you turn your signal on it will allow current to flow through your transistor from the collector ( Voltage source ) to the emitter ( GND ).


Normally you would have the device you are trying to switch connected by attaching the + to your voltage source and your GND to the transistor collector.

[norty303]

Thanks, I think David (DZ) may have come up with the fix for me.
By attaching 5V from my main supply to the collector on the transistor on the breakout board and removing one of the resistors on the breakout board he thinks it'll be enough current to operate the relay.
I'll be trying it as soon as I get in tonight. Fingers crossed!

I wish I knew a bit more about this stuff!!

The worst bit is doing this fix without the wiring becoming too ugly in the projectors as I have 5 to do! I knew it was all going too smootly...