ERD50
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
I'd like to find a simple, cheap way to monitor the running on/off time of some of my appliances.
One example - I really can't tell when my well pump is running. It is at the bottom of the well, completely silent in the house. Years ago, we had an underground leak, and it was running a lot. I didn't notice until the pump could not keep up with the leak and the pressure dropped.
I finally took some action on this - I connected a cheap, analog 1.5V quartz clock to the 220V well pump circuit. I used a wall-wart power supply rated for 110/220V, and a resistor divider to take its 5V DC output to ~ 1.2V, so the clock runs when the pump is powered. I set it to 'midnight/noon' each Sunday evening, and I'm finding it runs ~ 9-12 hours per week.
So that's 'solved'. But I'd also like one on our freezer and fridges. I recently did a long overdue manual defrost of our freezer. I monitored it with my Kill-a-Watt meter, and it was running ~ 90% duty cycle before defrost, and still about 80% after (freezer is in a hot garage at this point - duty cycle is far less in winter).
But that requires keeping the meter connected, and doing a calculation on the hours, kilowatts, and an estimate for the average 'on' watt draw. What I'd really like is something that tells me the duty cycle at a glance.
I haven't been able to figure out anything simple and cheap. The standard RC averaging network would be non-trivial with hour long cycles, and probably take weeks to settle. Everything seems to involve some fairly complex circuitry, and I just don't want to bother. I want simple.
A clock like on my well pump is probably the easiest, but would require more manual input with the high duty cycles. But I guess anytime I'm curious, just reset it at some point in the morning, and check 12 hours later.
Hmmmm, writing this spurred another idea. We have a few old ipods and smartphones laying around - if I were clever, I could actually write a little program for this. Tap the 120V circuit with a wall-wart ( isolated step-down transformer with AC output), feed that through a resistor divider into the mic input of the phone, and have the program sample every ten seconds or so to look for a voltage at the mic. With a program, you could do all sorts of running reports. Max and Min ON time, Max and Min OFF time, last ON/OFF times, duty cycle % for the past 8 hours, past 24 hours, past week, month, year...
I'd have to learn how to code for android or IOS though. But this might be a good motivator? I could put output jacks on various things I want to monitor, and move the phone around if I didn't want to commit an old phone to each appliance and monitor all of them 24/7.
Yeah, I know.... WDYDAD?
-ERD50
One example - I really can't tell when my well pump is running. It is at the bottom of the well, completely silent in the house. Years ago, we had an underground leak, and it was running a lot. I didn't notice until the pump could not keep up with the leak and the pressure dropped.
I finally took some action on this - I connected a cheap, analog 1.5V quartz clock to the 220V well pump circuit. I used a wall-wart power supply rated for 110/220V, and a resistor divider to take its 5V DC output to ~ 1.2V, so the clock runs when the pump is powered. I set it to 'midnight/noon' each Sunday evening, and I'm finding it runs ~ 9-12 hours per week.
So that's 'solved'. But I'd also like one on our freezer and fridges. I recently did a long overdue manual defrost of our freezer. I monitored it with my Kill-a-Watt meter, and it was running ~ 90% duty cycle before defrost, and still about 80% after (freezer is in a hot garage at this point - duty cycle is far less in winter).
But that requires keeping the meter connected, and doing a calculation on the hours, kilowatts, and an estimate for the average 'on' watt draw. What I'd really like is something that tells me the duty cycle at a glance.
I haven't been able to figure out anything simple and cheap. The standard RC averaging network would be non-trivial with hour long cycles, and probably take weeks to settle. Everything seems to involve some fairly complex circuitry, and I just don't want to bother. I want simple.
A clock like on my well pump is probably the easiest, but would require more manual input with the high duty cycles. But I guess anytime I'm curious, just reset it at some point in the morning, and check 12 hours later.
Hmmmm, writing this spurred another idea. We have a few old ipods and smartphones laying around - if I were clever, I could actually write a little program for this. Tap the 120V circuit with a wall-wart ( isolated step-down transformer with AC output), feed that through a resistor divider into the mic input of the phone, and have the program sample every ten seconds or so to look for a voltage at the mic. With a program, you could do all sorts of running reports. Max and Min ON time, Max and Min OFF time, last ON/OFF times, duty cycle % for the past 8 hours, past 24 hours, past week, month, year...
I'd have to learn how to code for android or IOS though. But this might be a good motivator? I could put output jacks on various things I want to monitor, and move the phone around if I didn't want to commit an old phone to each appliance and monitor all of them 24/7.
Yeah, I know.... WDYDAD?
-ERD50
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