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NPN 110/1.5a transistor NZT605 from Mouser — Parallax Forums

NPN 110/1.5a transistor NZT605 from Mouser

hmlittle59hmlittle59 Posts: 404
edited 2009-03-13 20:44 in General Discussion
Hello All,

I want to replace a Push Button switch(momentary) with an transistor. I've read a number of post from last Summer( May 2008) and printouts from the net. My understanding is that I should use a 1 or 10K ohm resistor from the BS2e in series to the Base of the transistor(protect the BS2) AND a pulldown resistor. The transistor will replace the switch on the back of a Garage Door motor. On for 1 to 2 sec. (high) and then (low). I've never used a transistor with out tying one pin directly to grd. should this work?

1) BS2e pin w/1k in series to Base of transistor
2) 1k to grnd in between BS2 and transistor
3) Collector and Emitter drop in replacement of Push Button switch, without either tied to Grnd
4) pins on back of Garage Door unit appears to be 5vdc

the transistor base would only be on for 1 to 2 sec.?


does this sound correct?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
I HAVE LEARN SO MUCH...BUT STILL KNOW SO LITTLE!!!

hmlittle59

Comments

  • Carl HayesCarl Hayes Posts: 841
    edited 2009-03-12 06:38
    In order to answer intelligently, one would have to see a schematic of the garage door opener.

    However, if you operate a relay with the microprocessor and use the relay contacts to operate the opener, you needn't know what's inside the opener.· Of course you'd use a transistor to operate the relay.· Very simple.· Cheap, too.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    · -- Carl, nn5i@arrl.net
  • hmlittle59hmlittle59 Posts: 404
    edited 2009-03-12 23:43
    Hello,

    I currently have a reed relay(SSR) and it works fine but they cost over $3.00, the transistor cost $0.70. I've also used 3 different optocouplers (NEC) one worked the others did not. I was using the transistor because of the current rating/price. I had already called the maker of my Garage Door unit and she explained that the switch operates a Relay.


    thanks

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    I HAVE LEARN SO MUCH...BUT STILL KNOW SO LITTLE!!!

    hmlittle59
  • rjo_rjo_ Posts: 1,825
    edited 2009-03-13 20:44
    So... there is a chance that if you just hook up your controller, you don't need anything else... of course, you could end up without a controller... but what is life, without a little smoke?
  • rjo_rjo_ Posts: 1,825
    edited 2009-03-13 20:44
    So... there is a chance that if you just hook up your controller, you don't need anything else... of course, you could end up without a controller... but what is life, without a little smoke?
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