Expo conv. heater (tomg et al.)

[tomg]

----------
> From: tomg <vco at mindspring.com>
> To: Mark Smart <smart at nn.com>
> Cc: synth-diy at mailhost.bpa.nl
> Subject: Re: Expo conv. heater (tomg et al.)
> Date: Tuesday, February 02, 1999 2:08 AM
> 
> 
> 
> ----------
> > From: Mark Smart <smart at nn.com>
> > To: synth-diy at mailhost.bpa.nl
> > Subject: Re: Expo conv. heater (tomg et al.)
> > Date: Monday, February 01, 1999 8:03 PM
> > 
> > I've been messing with a circuit using a heated exponential converter
> > lately, 
> 
> [snip]
> 
> > 1. Reduce the current-limiting resistor on the heater transistor to
below
> >    33 ohms (with a 15V supply). Maybe this would blow up the
transistor.
> It
> >    says in the databook that the limit on the collector current for the
> >    transistors in a 3046 is 50 mA...15 volts/33 ohms is 455 mA! ???
> 
> Ohh I see.. You can't do it with a single supply....well not a 15V supply
> anyway maybe 30V or so.  You could ground the emitter and still not get
> enough current to heat up the 3046 at +15. Put a meter in there and see
> what you get. I bet it's like zero. Try a split supply.
> -tg
> 

Forget all of that crap! Sorry try this. Heats up fine from a single
supply.

http://www.mindspring.net/~vco/misc/pics/hr2-3046.gif

-tg