Strange to relate, I have two sat on my drawing room table as I write.
One looks like a relay but contains a synchronous motor, a gearbox and an adjuster calibrated 0-10. Push a button and it runs for the set time up to ten seconds and then stops.
Another is much larger and has a rotary scale going from 0-100. You turn a knob to the desired time and, when you push a button, a relay operates and the knob rotates back to zero, when the relay de-activates. The knob scale actually has an outer ring that can set the time from 0-100 mS,
0-1 S, 0-10 S, 0-100 S, 0 -1000 S and 0-10000 S - by changing gearbox ratios.
I only mention those because I am trying to find a use for them and, if you lived anywhere near me in darkest Devon UK, you could just have come and collected one for free.. They came out of equipment that I had stripped down.
I was going to use the big one in a box supplying power to a socket for my electric clothes iron - as I am for ever leaving the thing on...
However, I digress. I think the thing you need is a "darkroom timer".
electric flow for that amount of time and shuts off.
out of the question.
push the button the timers is set for that length of
Intermatic makes one that runs about 10 minutes per switch operation. I have one on my bathroom fan. The other easy option is a spring would timer. If you want to make something look at the circuits they cobble up from a 4060 CMOS counter and a relay, solid state or mechanical. This guy has some samples of what you can do
The big problem with Chagford is that it is a sod to get to in a bus in mid-Summer...especially if you are the driver. Still, the look on some people's faces when they round a corner and find a hedge-to-hedge bus coming at them is something to treasure.
There is a little spot not too far from there that really is an almost entirely undiscovered wonder. A public path starts by going through a very uninspiring farmyard. A short walk later, you are beside a little river tumbling down a hidden valley, complete with deep pool to go swimming in. I've been going there for years and never seen a soul, other than from the farm...
Come on Sue! If you want REAL excitement in a bus, let the driver go off the side of a mountain between Ft Greely and Fairbanks, Alaska while the passengers scream for their lives. I missed that ride by two weeks, in the mid '70s. Sam bus, same route, and same driver, with friends of mine aboard. They were all SURE they were going to die. :(
It dropped a couple hundred feet, and was caught by a large tree. A few ended up in the hospital, but no one died.
electric flow for that amount of time and shuts off.
out of the question.
push the button the timers is set for that length of
Depends on your specific application.
If you specified operating volts, AC or DC, current, accuracy needed, etc. you might receive a specific answer.
For low accuracy on low voltage DC I use a simple power FET transistor with a capacitor/resistor on the gate, a relay, and a SPST switch. The resistor can be a variable that you adjust to set the time. If the load is DC and not harmed by a slow turnoff, the FET can drive it directly. If brewing your own, look at the old LM555 timer circuits for more accuracy and a definate snap action.
There are 2-inch square timer blocks with a series of small switches to set the time, but they are specific to a voltage and load current. Bill Kaszeta Photovoltaic Resources Int'l Tempe Arizona USA snipped-for-privacy@pvri-removethis.biz
the electric flow for that amount of time and shuts
Google 'Time Delay Drop Out'.
You will have to check out the specs on each relay. Some 'consume' a small amount of power while waiting for the start command even though their controlled contacts are open (pass no current) until the period is initiated. You will have to define exactly what you mean by the timer not 'drawing power'.
the electric flow for that amount of time and shuts
If you just want a one shot, the simplest way is a capacitor discharging across a darlington with a pot to fine tune the discharge time. If you are holding up a relay through a normally open contact you can drive any load the relay can handle. Dropped out, it is an open circuit
The Devon, Cornish and a lot of Welsh roads are good for getting in a lot of reversing practice ! :-)
Not too bad in a car or an elderly Espace like mine but.....
Sounds nice. I'm afraid the weather did dampen our enthusiasm a little for walking. We did one walk around Buckfast, mostly through woods, following up with a visit to the Abbey and even when in the open the rain wasn't too bad that day. The Friday before we left was dry and we managed to get up on the moors near Princetown.
We will probably be heading down in that direction again next year but whether to Chagford or somewhere else has yet to be decided.
The Devon, Cornish and a lot of Welsh roads are good for getting in a lot of reversing practice ! :-)
Not too bad in a car or an elderly Espace like mine but.....
Sounds nice. I'm afraid the weather did dampen our enthusiasm a little for walking. We did one walk around Buckfast, mostly through woods, following up with a visit to the Abbey and even when in the open the rain wasn't too bad that day. The Friday before we left was dry and we managed to get up on the moors near Princetown.
We will probably be heading down in that direction again next year but whether to Chagford or somewhere else has yet to be decided.
BTW.
Does this little group of children here /ever/ stop hurling obscenities at each other?
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