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    Need to pull item against a spring, fast. How to pick a "linear solenoid" ?

    Solenoids are rated in watts as in horsepower with 1hp=746watts. As you will be able to measure the pulling force required and you will know the time required to move the device, then you have the 2 necessary measurments to calculate this. hp (watts) is work done in a certain time. e.g. 1hp =...
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    help with simple picaxe problem and LED

    That was the idea and the reason for the diode was no one really knows what is going on inside of the "puck" except that it drives an LED which is esentially a diode and I was trying to copy this loading. Didn't notice the constant current bit though so maybe my idea is not applicable. The chart...
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    help with simple picaxe problem and LED

    Didn't see any minimum current in the chart so perhaps a series diode and a high value resistor across your existing LED?
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    Wire size for current?

    12 gauge around 20 amp and 14 gauge around 12-15 amp but depends on your route length of cable. At low voltages the cable resistance becomes rather important. One can find the cable.... voltage drop per amp meter.... in cable size tables (not really familiar with gauge sizes as we use mm2 in Aus.)
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    About Servo Motors

    As Gryd3 says, 555 timer and a couple of switches. mmm...no switches or linear ic's allowed. Still, ldr could make the timing change and from memory one can get a 741 or similar to do the timing.....just not as simple and simple is another required parameter.
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    Need help with long distance circuit

    Perhaps an opto isolator at the alarm end feeding a relay. Only the opto current flowing in the long run via the float switch. In the past, when running long distances (around 1 klm) between pump station and turkey nest , we used probes at the "float end" and probe relays at the "alarm end". May...
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    Looking for a 3PDT Rocker switch

    Use existing switch and relay perhaps.
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    Where do I go now to learn more? (Self taught prop/toy maker)

    Maybe watch these tutorials on Arduino....the mind seems to kick in sometimes when one sees the possabilities of a particular system. Start at No.1 and work your way through ( I think about 15 in all) Clone boards are available from China for a cheaper alternative to originals.
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    Shock Sensors

    Why overcomplicate the circuit. If you want the above then just a microphone and small amp with the microphone taped to the wood block ?
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    Run this 1.5v pump from a 18650 battery

    3 x !n5401 diodes (3 amp 100v) in series with the motor.
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    Automobile charging circuit light circuit

    The way the old generator indicator bulb (charge light to some.......ignition light to others) worked was to place it in circuit with the dynomo (D) terminal of the generator ( usually through and ignition switch) and the pos terminal of the battery. At rest the current would flow from the...
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    Adding "on" light to 240V thermostat

    GFCI (Earth leakage) operate on earth leakage current,i.e. an imbalance between line and neutral current, not on balanced line to neutral current as it would be if connected line to neutral.
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    Charger connector needed

    :eek:.......Like the temporary wiring with the attached warning...good one....wonder if that was intentional......:)
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    Aqualisa Lumi 10.5kw no power

    Wonder if this one does.:)
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    Aqualisa Lumi 10.5kw no power

    Don't be surprised if it is only single phase. We recently had a call to a cafe which had a new instantaneous heater installed by a plumber and plugged in to a standard power outlet. Didn't work in that outlet so they proceeded to alternatively plug it into every outlet in the shop. Turned out...
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    Wire, 0.22 mm² CSA , 1000 V 1.4 A assorted colours...

    Think you will find the "1000v" part of your initial requirement is what makes the cable both expensive and difficult to find at local electronics stores.
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    Issue with supply not turning off sometimes

    You may well be an electrical engineer but you fail to answer my query. The reason I bring up the concern is ...if your PSU output is 240V AC then, not only are you creating a dangerous and illegal situation, but your mains supply and your PSU supply can very rarely (if ever) be in phase with...
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    What is a 'High/Low Level Trigger'?

    Depends on the PIR. We often get problem installations with respect to trees and clothes lines etc. Even though the units we use have sensitivity adjustment, we tend to avoid the above like the plague as it tends to give false triggering. i.e. wind blows the branches.........receiver detects hot...
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    Is this device a thermistor?

    Doubtful...thermistors are usually small bead type devices buried in windings of motors or in battery packs etc. Can be encased in small metal casings with tabs to conduct the heat/cold into the device. What made you come to this conclusion?
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    Issue with supply not turning off sometimes

    Am I correct in assuming the PSU is generating 240v ac from the 12v dc on the left of your diagram? If this is the case then a word of warning about pumping 240v ac back into any supply system, dangerous and illegal practice.
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