N&V High-side switch

[mojorizing]

The high-side switch depicted in the May 2006 edition of N&V, page 27 doesn't seem to work on my Electronics Workbench simulator. There's must be a typo. What's wrong with that circuit?

I need a high-side switch to activate a reset line going to a reset pin of MCU, so load is minimal.

Thanks, Kevin

[philba]

I gave up supscribing a while ago so I can't help you with that circuit but why would you need a high side switch? Most uCs have a reset pin that is active low. Pull it low to reset the chip. You can use a cheap NPN transistor for that in a low side configuration.

If you could post your schematic, I'd be happy to look at it though.

[bodgy]

As Philba says, posting a schematic would be helpful.

However a high side switch would normally be a PNP BJT with emitter to + supply - base to a pos -> neg supply (neg = on) and the load to be switched in the collector lead with a resistor to the - terminal.


Colin

[philba]

Here's the basic idea for high and low side drivers