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This simple throttle circuit for medium power motors uses two older style transistors, which should be mounted on a heat sink as the output transistor drops considerable power at slow speed.
The rectified voltage is stored on a capacitor to smooth the output. The cut-out holds any short circuit condition to under 2 amps. Enough to melt turnout blades if left on for any period. But not to cause an explosion.
The rectifier should be a 4 amp rating.
A boost push-button switch is useful for low speed starting as it introduces a higher voltage pulse to kick the motor over. Only use a quick push of the button or the loco will jump away.
---- Running report
Starts at a higher speed than it runs unless the Pulse button is used. Slow speed running OK. Control dead band a little high.
This simple throttle circuit for medium power motors uses two older style transistors, which should be mounted on a heat sink as the output transistor drops considerable power at slow speed.
The rectified voltage is stored on a capacitor to smooth the output. The cut-out holds any short circuit condition to under 2 amps. Enough to melt turnout blades if left on for any period. But not to cause an explosion.
The rectifier should be a 4 amp rating.
A boost push-button switch is useful for low speed starting as it introduces a higher voltage pulse to kick the motor over. Only use a quick push of the button or the loco will jump away.
---- Running report
Starts at a higher speed than it runs unless the Pulse button is used. Slow speed running OK. Control dead band a little high.
LINK TO IMAGE - cab-simple.gif
Circuit Schematic
