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Can someone give me some advice on how to hook up a relay driver and what relay driver to use? I'm driving a 5 volt relay that in turn drives a small motor that is heavily geared down to drive a small forklift up. It's for a light weight robot ("Little Bug")that will be competing in BotBASH in May. I'm controlling the fork with an IR remote and then stopping it with some limit switches. Pretty simple, everything is working, but I didn't realize that the BasicX couldn't supply directly the 90mA that the relay sucks out. Also, I think the BasicX was getting a little hot in the process of this discovery. At what point should I start to worry? Thanks Chuck P.S. - actually, I'm driving two relays. Chuck Pitzer Design and Simulation Specialist Pitzer Consulting 1221 W Bartlett Way Chandler, AZ 85248 Mobile - (602)524-9850 Office - (480)802-6675 Fax - (208)728-8395

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Chuck, All you need is a single NPN transistor; 2N3904 or better yet a TIP31 or TIP41. collector ---- relay coil ----- +5 ------->|-------- 1N4004 diode BX24 ------ 330 ------ base emitter to ground When BX24 output is at logic one, transistor turns on, operating relay. When BX24 output is at logic zero, transistor is off. The diode across the relay coil suppresses inductive transients when the relay is released. Peter H. Anderson, Morgan State University , http://www.phanderson.com/basicx/ -----Original Message----- From: Chuck Pitzer <> To: BASICX ONELIST <> Date: Thursday, April 06, 2000 3:18 AM Subject: [BasicX] Relays :Can someone give me some advice on how to hook up a relay driver and what :relay driver to use? I'm driving a 5 volt relay that in turn drives a small :motor that is heavily geared down to drive a small forklift up. It's for a :light weight robot ("Little Bug")that will be competing in BotBASH in May. :I'm controlling the fork with an IR remote and then stopping it with some :limit switches. Pretty simple, everything is working, but I didn't realize :that the BasicX couldn't supply directly the 90mA that the relay sucks out. : :Also, I think the BasicX was getting a little hot in the process of this :discovery. At what point should I start to worry? : :Thanks : :Chuck : :P.S. - actually, I'm driving two relays. : :Chuck Pitzer :Design and Simulation Specialist :Pitzer Consulting :1221 W Bartlett Way :Chandler, AZ 85248 : :Mobile - (602)524-9850 :Office - (480)802-6675 :Fax - (208)728-8395 : : :------------------------------------------------------------------------ :LOW RATE, NO WAIT! :Get a NextCard Visa, in 30 seconds! Get rates :as low as 2.9% Intro or 9.9% Fixed APR and no hidden fees. :Learn more at: :http://click.egroups.com/1/937/4/_/565855/_/955005524/ :------------------------------------------------------------------------ : :

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