I often have to use an NPN transistor (emitter on ground) to turn on a PNPtransistor (emitter on +B) to efficiently switch positive voltage. Is there adevice that can replace the two transistors and two resistors required to switchthe +B supply?The required collector current would be less than 500ma and the Vce would beless than 50v. Ideally, it would be a 4 legged device that would be in a case similar in sizeto a TO-92 device.I know that an opto-isolator could do it but they're too expensive in mostcases. Thanks in advancePB--------------= Posted using GrabIt =----------------------= Binary Usenet downloading made easy =----------= Get GrabIt for free from =-

Yes there are many, using MOSFET high-side switch architecture, with onboard current- and thermal-limiting circuitry. Oops, not in a TO-92. Small SMT is available though. Typically thay have 5+ pins, the 5th being used for a status info output.-- Thanks, - Win

"Arie de Muynck" schreef in berichtnews:42aadf61$1$70907$Ai, there goes the coffee and the donut.-- Thanks, Frank.(remove 'q' and 'invalid' when replying by email)

Is there a device that can...

Jun 05, 2005 42 Replies

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Rich The Newsgroup Wacko 21 years ago

Buy a copy of his book. ;-D

Cheers! Rich ------ "Sex is the poor man's opera." -- G.B. Shaw

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Arie de Muynck 21 years ago

"Frank Bemelman" ...

If EVER that BC junction shorts you will blow the micro. Done it, got bitten, came back...

Arie de Muynck

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Frank Bemelman 21 years ago

"Arie de Muynck" schreef in bericht news:42aadf61$1$70907$ snipped-for-privacy@news.xsall.nl...

Ai, there goes the coffee and the donut.

Thanks, Frank. (remove \'q\' and \'invalid\' when replying by email)

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