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DPDT Timer circuit i.e. Momentary ON (+6v pulse) then OFF for 10 sec's then Momentary ON (reverse pulse) Answered

I need to toggle a solenoid between 2 positions. It isn't spring loaded so needs to be powered between states i.e. a +6v and GND pulse to the coil then wait 5 to 10 sec's before sending another pulse but with the polarity reversed.

Simple to do with a 'Mom-OFF-Mom' double pole double throw toggle switch e.g. JAYCAR Switch Tgl Mini CTR-OFF DPDT MOM
CAT.NO: ST0358 but I would like to be a bit more automated. 

Ideally the cycle will start at power on and then automatically repeat every 30 min's or so but if that makes it too complex, then a momentary push button switch could be included to manually initiate the cycle.  


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Nighter3D
Nighter3D

4 years ago

hmmm. for small timing i would suggest to look at 555 timers, but they get far less reliable when dealing with time in the scale of minutes.

So you want to Pulse once, then pulse in reverse at a reliably time?? Hmmm. Well for handling the power i would suggest to look at H-Bridge drivers. H-Bridge drivers are handy as act a bit like a DPDT switch.

For time... Well you could use a bunch of 555 timers to act as timekeepers with them triggering eachother, tough that may not be the best option (not very precise), there are also other solutions, but if you want it to wait 30 minutes?? Well personally i would edge towards the use of a microcontroller that controls the Driver. would be more reliable and precise then a analog timer.

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steveastrouk
steveastrouk

Answer 4 years ago

I've found them....reliable....just very, very inaccurate ;-)

The classic method is to run the 555 at some nice binary multiple of the the frequency or period you need then divide it down. You used to be able to buy special 555 with the divider built in.

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Downunder35m
Downunder35m

4 years ago

Why not simply use a latching relay?
One pulse locks it in one position, next pulse in the other and so on...