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I need a relay/switch, which would have a push-button switch upon which the button is pressed, it would power an appliance on.

I have a water pump, and its water pressure switch is defective. I would like to make it such that I can switch it on for 10 minutes, and it automatically switches off after the 10 minutes have elapsed.

What is this type of relay/switch called? This is not to be confused with a 'timer', which would say switch on an appliance at a given time every day, like those which are sometimes used for Christmas lighting, where you can switch it on at 5 pm and automatically turn off at 11 pm.

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Those switches are called delay timer relays.

For instance, see the Omron H3Y, sold on eBay for $8 or less:

Omron H3Y Delay Timer Relay

Your application would require a relay with 10 minutes or more on the setting range, and you would need to ensure that the specific relay / relay base you buy are rated for inductive loads sufficient to cover the pump's starting / stall current rating.

Note that the sample image above is rated for 5 Amperes 250 Volts AC resistive load, not the rating applicable to your requirement.

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Try looking for a "timer delay" circuit. These can be implemented using transistors, 555 timer integrated-circuits, or in the most general case microcomputers. For example, this timer delay circuit lights up an LED when a push button is pressed and stays on for an undefined amount of time depending on the value of the capacitor in the circuit.

For a time-delayed switching of a relay, however, you will need to be careful. For one, relays require a lot more current than LEDs, and you will need to choose a timer circuit that accounts for that requirement. Additionally, make sure that you include a protection diode when switching an inductive load like a coil relay or risk damaging your relay and your circuit.

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It is a timer in any case, and you can find it as an electromechanical part. From a more electronic point of view such a circuit will be identified as a monostable, and it is easy to create with a 555 chip. You can use the monostable example, but being accurate with a 10 minute time will require a tantalum capacitor.

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