Expo conv. heater (tomg et al.)

[tomg]

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> 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