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    Parts list - help us find parts.

    "Sorry this store does not exist"
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    Police Lights

    The 470 ohm resistor is to pull the output down when it's not high so the transistor switches off. Sorry it's a bit late in answering
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    Auto Plant waterer

    Gave up
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    Auto Plant waterer

    Project on hold awaiting graphite rod..
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    Auto Plant waterer

    Works for a while until ions build up on the sensor anode and rots it off (electrolysis) Think I'll have to use a graphite rod as a sensor
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    555 timer resistor

    Have you put a power supply to the 4017 chip? Also a small capacitor across the power supply like 10nf
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    Auto Plant waterer

    No it never switches back on until the compost is about 500k ohms. Compost is quite dry at 150k ohms and wet through is about 20k ohms so I've changed a resistor (I may fit a multi-turn pot later) hooked a submersible pump up and testing what is a fully functional prototype...
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    Auto Plant waterer

    Well things have certainly been quiet round here. Has everyone gone to Facebook? Let's get posting again Today I made a 555 circuit to automatically water my chilli plants. It's not finished yet, I'm just testing if it switches on/off reliably when the compost dries out and rewets ️
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    Syncronize two strobs

    I would look at using the decade counter from my police lights thread. Look into using outputs 1&2, then leave 3&4 unused, then use 5&6 and then reset on output 7
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    Switching a 12v dc motor

    Anoop your English isn't very good. My head hurts trying to read that.. Have you got a diagram?
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    Police Siren

    Maybe the breadboard is faulty. I always use veroboard. You can't beat proper solder connections.
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    Dark Detector

    Nothing will change much. Just check the LED resistor on the internet calculator wizard.
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    Music Box

    4017 is a decade counter IC
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    Wiring in a monostable 555 timer trigger to a car ignition

    This forum is dead. Try posting on 'all about circuits' forum Rich
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    Interested in inverter circuit

    Lol I've just googled it... "Bust some suds"..."Crack some suds" tee hee, never heard of beer being called suds before, suds are usually soap bubbles here. Anyway I always chill my suds, you must have met some old men while you were here, they drink the disgusting warm suds from the hand pumps. Urgh
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    Interested in inverter circuit

    I commend your enthusiasm but to build an inverter to drive a water pump that you would rather want to work reliably is going to be difficult. Don't get me wrong, the simple 555 circuit above may very well work in theory, but you would be much better off buying a decent 'pure sine wave' inverter...
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    Interested in inverter circuit

    If you look up 'Astable' on Wikipedia it shows a circuit very similar to the inverter circuit but without the output stage. There are some calculations listed that will show you the correct resistors and capacitor to use for 60hz. The output may not be very sine wavey and to get any kind of...
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    Interested in inverter circuit

    Yes, either move to Britain or change it to 60hz
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    Open and close curtains a simple circuit

    How about using 2 motors 1 for opening, 1 for closing. Instead of a 555 timer just put limit switches up on the rail.
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    Display cabinet - pir motion sensor & led circuit 555

    You would be best off buying a battery powered PIR lamp (osram make them) and using that. I've got one in the garage, the batteries last years.