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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Triac/Thyristor delay off timer.
I'm looking for a circuit for switching off a Central heating pump after a
delay up to (max) 2 mins adjustable (after boiler has ceased firing) using SCR , Triac or similar, 240 V @ 2Amps approx max. regards Tom |
#2
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"Tom" wrote in message ... | I'm looking for a circuit for switching off a Central heating pump after a | delay up to (max) 2 mins adjustable (after boiler has ceased firing) using | SCR , Triac or similar, 240 V @ 2Amps approx max. You should be able to find an industrial timer to do this. N |
#3
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In article ,
"Tom" writes: I'm looking for a circuit for switching off a Central heating pump after a delay up to (max) 2 mins adjustable (after boiler has ceased firing) using SCR , Triac or similar, 240 V @ 2Amps approx max. You can buy run-on timers for bath/shower room fans. You might have to uprate the triac as such fans are normally only around 20W. Standard domestic central heating pumps are normally only up to around 120W on max setting which is a lot less than your 2A. -- Andrew Gabriel |
#4
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I'm looking for a circuit for switching off a Central heating pump after
a delay up to (max) 2 mins adjustable (after boiler has ceased firing) using SCR , Triac or similar, 240 V @ 2Amps approx max. You can buy run-on timers for bath/shower room fans. You might have to uprate the triac as such fans are normally only around 20W. Standard domestic central heating pumps are normally only up to around 120W on max setting which is a lot less than your 2A. Andrew Gabriel Thanks Andrew, I like to have a high factor of safety in my little circuits, for a one off for my own use the extra cost is immaterial. However, Set square has come up with a nice solution on uk.d-i-y using a pipe stat. I think it may work, any observations? Best Regards Tom |
#5
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"Tom" wrote in message ... I'm looking for a circuit for switching off a Central heating pump after a delay up to (max) 2 mins adjustable (after boiler has ceased firing) using SCR , Triac or similar, 240 V @ 2Amps approx max. You can buy run-on timers for bath/shower room fans. You might have to uprate the triac as such fans are normally only around 20W. Standard domestic central heating pumps are normally only up to around 120W on max setting which is a lot less than your 2A. Andrew Gabriel 120W? More like 1200W for a 1/2HP blower commonly used for circulation with the heat pump. The condensing unit itself draws significantly more than that. |
#6
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In article MW19d.8681$x65.5242@trnddc06,
"James Sweet" writes: 120W? More like 1200W for a 1/2HP blower commonly used for circulation with the heat pump. The condensing unit itself draws significantly more than that. You're talking about something quite different. -- Andrew Gabriel |
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