Circuit setups for pulse motors

[Thaelin]

Hi all:
   Also take notice that an NPN transistor turns on with a positive going pulse, PNP uses a negative pulse.

thaelin

[Ren]

Please clarify Thaelin? If a pickup coil is being used this would come into effect, but does this also efffect hall circuits? A pnp will fire when it receives a negative impulse from the hall? Is this in reference to waveforms/ scopes?

[tropes]

Hi all:
   Also take notice that an NPN transistor turns on with a positive going pulse, PNP uses a negative pulse.
thaelin

Thaelin
Perhaps you could upload or point out where I could find a circuit using PNP transistor that would make the Hall switch less prone to damage?
Tropes

[Ren]

tropes, our original hookup works. The link provided by toad shows us how to isolate the hall circuit from the firing circuit. Think of the trigger on a gun. Our setup has the trigger in the barrel everytime we fire! Toads diagrams show by hooking up the top of the coil to the collector (instead of emitter) isolates the trigger from the barrel so to speak.

I just hooked up the hall to my pnp with the coil connected to the collector  and emitter connected to ground. It works good, but I am no longer seeing the high voltage spikes on my multimeter when I connect it to the collector and emmiter. Voltage just sits at about 10v. Maybe I need to install diode as per Nastrands diagram for collecting to a cap. So many things to learn....

[hoptoad]

tropes, our original hookup works. The link provided by toad shows us how to isolate the hall circuit from the firing circuit. Think of the trigger on a gun. Our setup has the trigger in the barrel everytime we fire! Toads diagrams show by hooking up the top of the coil to the collector (instead of emitter) isolates the trigger from the barrel so to speak.

I just hooked up the hall to my pnp with the coil connected to the collector  and emitter connected to ground. It works good, but I am no longer seeing the high voltage spikes on my multimeter when I connect it to the collector and emmiter. Voltage just sits at about 10v. Maybe I need to install diode as per Nastrands diagram for collecting to a cap. So many things to learn....

Greetings one and all
I'll have to be quick - very pressed for time due to work commitments. the spikes should still be there, but now instead of seeing them across your collector to emitter junction, they will appear across the coil from the +ve supply rail to the base of the coil (NPN arrangement). I will try to add some more info to my web page tonight if I'm not too tired.

Cheers for now and happy motoring - the Toad who Hops