TVS vs Zener diode

[Sandy]

At 08:19 PM 5/27/97 -0700, you wrote:
>I am wondering if anyone out there has used a TVS (transient voltage 
>supressor) instead of a Zener diode to protect the transistors switching 
>the injectors on and off.  To be a bit clearer, on the schematic supplied 
>with a National Semiconductor LM1949, they show a 5w 33v zener used to 
>protect the darlington circuit  switching the injector current.  I 
>am wondering if anyone has used a 5w 33v TVS instead (couldn't get a 
>zener!) I am wondering really, if anyone has tried and had it fail to 
>operate properly.  The injectors used are bosch/dodge neon, with a static 
>resistance of 12.3 ohms.  
>

Yes, I have used it, and it seems fine, one problem is the extra cost, and
the part is has a bit larger leads then the 5watt zeners. It seems to work
ok when I tried it with the LM1949 boards that I designed. Also the zeners
are available from Newark, but you may have to get $20 or some minimum order.

Sandy