pulse motor and hall efffect circuit

Thread Starter


Joined Mar 1, 2008
Hi all,
i am building a pulse motor with six north facing magnets.
i am using a hall effect switch as the trigger to fire the coil, but i am having some problems with the circuit.
i connect up the circuit and i do not get a pulse. But when i remove the diode from the power transistor. the power transistor saturates, and stays on.
if i remove the 1K resistor, again nothing happens to the circuit, but when i replace the resistor the transistor saturates. i have tried a few resistors but with no luck,
my power transistor is a 2SD729H
power supply is a 12 volt motor bike battery
can any one help please.



Joined Jul 17, 2007
Which Hall-effect switch are you using? (There are a LOT of different Hall-effect switches out there.) Link to the datasheet for it, please?

You don't show the connection to +12v for the 1k resistor and the coil/diode combination. Didn't you mean to connect them?