Need Wiring Help For 12 Volt Motor

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bertie_bassett:
had a lil bit of time to play around with a modified circuit and this is the best i can come up with

2 options for the pwm circuit, either an added diode, or an extra switch added on the back of the joystick.

personally id try to modify the joy stick for an extra contact.

vtsteam: i dont think your extra power supply will work as drawn as its putting a permenant supply onto the pwm output so you wouldnt get any slow speed

vtsteam:
Bertie, I like your diode version. And better than the switch version, since the problem was to do this with joysticks, not switches.

I'm not 100% clear why my circuit would do as you say, but one problem with the drawing (pointed out back a ways by 75 plus) is that I showed the joystick contact as closed and the relay is shown in its un-energized position. This might be why I'm missing what you're saying, because I'm back at the head-hurting stage trying to imagine what happens with the relay energized, or the joystick in the opposite contact (to make the drawn schematic consistent).

Likewise, I'm having a hard time imagining that effect on yours since you used my same schematic. Both need re-drawing. But in principle, I like your diode method.

The easiest change to the drawings to make them consistent, would be to draw the joystick common (arrow) going to the lowest contact rather than the upper one.

vtsteam:
velocette, yours works but doesn't fit the requirements for a high speed joystick and a low speed joystick, each with a center off position.

velocette:
The motor is always started on Low speed Then engage the second momentary switch On the joystick to Give high speed by shorting the speed Pot.
A lot less load on start up than reversing at full speed. Works For Me
Eric

bertie_bassett:
sorry for the confusion, when i mention switches, i was refering to the contacts on the joystick itself. in this case there are 4 seperate N/O contact blocks. easiest to think of them as 4 seperate switches.

vtsteam: your drawing with the joystick closed but relay de-energised is a bit confusing, but dosnt really effect much. The modifications i drew up from your drawings, accounted for this and should work as drawn. ( the origional fast speed would need minor wiring changes, but nothing major)

as iv drawn things it dosnt really matter what state the relay is in, your primarily turning the pwm modual on to power the motor, direction is a secondary affair.

the biggest problem with PWM is that its basically just turning the motor on and off very fast, so if you were to feed a relay with it, it would be going on off on off on off which i doubt it would like at all.
adding a constant power supply onto the same rail would just override the PWM as there would no longer be the 'off' section.

overiding the pwm was basically what my origional idea was, get things moving in the direction required at slow speed, then override the pwm to speed things up a bit!

hope that clears things up a bit.

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