BS1 to control electric RAM

Garth

Hi. I am trying to use a BS1 to control a Dyadic Systems ram (SCN5-010-050-AS03). The RAM is pre-programed (internally) and a contact closure executes the pre-program instructions. Control is a 24vdc sync signal. I was thinking of using the circuit attached to accomplish this. I'm still new at this so I'm looking for any input anyone is willing to share.

Thanks in advanced.

Garth

erco

I'll bet·your 100K transistor is too high-value and your transistor is probably not rated for the current that the ram·might draw.·Suggest instead you·use a TIP31 power transistor with a 220-330 ohm bias resistor. Better yet, without knowing the ram current,·it's·safer to·use a 5-volt relay. Use the same circuit you have, change your bias resistor from 100K to 330 ohms, and use that 2N3904 transistor to close a relay like Radio Shack 275-240 or bigger, if you can find one.· That is, stick the relay where your ram is in your drawing, powered by 5 volts, then use the relay contacts to switch 24VDC into your ram. Add a reverse-biased (backward) silicon diode across your relay coil to kill voltage spikes.

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·"If you build it, they will come."

Garth

Thanks for the response. I made one mistake, the control is source not sync. (Damn. lol) The draw is 4ma and there are 5 inputs all together so I was trying to avoid relays for space concerns. I'll have to switch to a PNP transistor instead.