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I know nothing about this stuff but I need to create a circuit that limits the duration of a connection through a DPDT switch. What I want to prevent is someone holding the switch in the closed or hot position for to long and burn up a motor running on 9volts. The duration should be about .66 of a sec in either direction. I would also like an LED to glow if power is on in either position. So the functions are push forward and the motor rotates in one direction. Push back and the motor turns in the other direction. Can you help me create such a circuit?

Does your DPDT switch have a Centre Off position?

Could you use two push buttons instead: one for forwards, one for reverse?

Thinking about this, you must have either a centre off switch or two speparate push buttons.

Otherwise you cannot do:

forwards for 0.66s then forwards for another 0.66s;

or

backwards for 0.66s then backwards for another 0.66s.

You can only do alternate forwards-backwards-forwars-bcakwards etc.

What do you want to happen if the switch or button is released (off position) before the 0.66s is elapsed?

What do you want to happen if the motor direction is requested to be changed before the 0.66s turning in the current direction is elapsed?

What current does your motor draw?

Yes the switch has a center off position...The devices that I'm using are old hard drive to first open/block and then closed/unblock a video projector.

I am using a 9 volt power supply. I have constructed the switch and all works OK. The new issue is to some how prevent someone from holding the switch in either position on of off for to long thus burning motor or creating to much noise. As for the duration of the timer it is based on the close rate of the motor and this is based on the specific gearing of each unit. Again the ideal would be to be able to vary the timing.

The ideal would be if the external switch simply started the process...all other functions were handled internally including switching polarity for the voltage to reverse function of the motor.

Voltage of the motor may vary as well based on the fact I am using trashed DVD drives made by various manufactures as the shutter. Here to the ideal would be to be able to vary the voltage.

What would be very sweet is if this could all be controlled by the use of 3 pin DMX control.

Can you have 2 limit switches that detect when the shutter reaches fully open and fully closed?

Or a pair of IR proximity sensors?

Or one sensor and two holes in the shutter?

And yes it can be done using DMX but you'll need to find someone who knows about it.

If you are willing to pay I can put you in touch with someone who does it for a living.

Worth talking to for sure cause I know nothing about this stuff, Thanks

You'll get nothing for free from this guy so the question stands: are you willing to pay market rates for a professionally designed and produced unit?

:)

Well funding is my own pocket and I will decide the quality and standards employed. As for paying for the produced unit I will need to discuss cost and "Market Rates" to determine Value. There are commercial units out there so any unit will need to provide benefit. My email is rdurie999@gmx.com

City Theatrical 4160 Projector Dowser ‑ $448.50 So you see it has to be cost effective. web link to the commercial product

http://www.fullcompass.com/product/375240.html?utm_source=googleps&utm_medium=shopping&utm_campaign=googleps&gclid=CPyNmMy09rYCFQgx4AodsE0ATQ