What appliances do you monitor
- Thread starter mbreeden
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Guy Lavoie
Active Member
I have a standalone program that logs all HVAC activity: HP compressor on, reversing valve, defrost, electric heat, oil heat, high electric rate, fan. I also log the inside and outside temperatures every half hour. This uses whats known as a Peter Anderson kit which consists of a PIC that reads Dallas 1 wire sensors and is interrogated by a serial port by my logging program.
Rupp
Senior Member
I did put a temp sensor in the freezer in the garage. This way if it goes above 20 I get an email. Other than that there's not much else to monitor. I guess one could monitor it the oven was left on for a long period of time. I also control an electric heater in the bathroom but I really do not monitor it.
jwilson56
Senior Member
I have not had much luck using the current sensor for the washing machine. It works great on the dryer. The washing machine starts and stops alot during the varous cycles. My new one has a buzzer on it for end of cycle so I am thing I could tie into that once the warrenty is up. I did however put one of those washer-buddies on it to shut it off in case of the laundry tub getting to full.
John
John
I noticed my new washer has a 'door locked' light, which would be perfect, but since it's under warranty too now, I don't want hack it apart. Is there a cheap sensor which can be hooked to the Ocelot and can placed on top of that light to detect when it's on/off? BSR mentioned he had the same issue with his washer machine & current sensor setup.
BraveSirRobbin
Moderator
Maybe someone like Guy Lavoie can give us some insight on any experience with a phototransistor to help monitor your LED for your washer and how to hook it up to the SECU16 (hint hint, Guy!!!).
As far as the washing machine monitored with a current sensor, its going to be difficult because when the machine is filling with water (i.e. no pumps or motors working) it only has a solenoid "on" and draws milliamps of current, which is difficult to monitor with the current line of inductive current sensors. You could try something like a timeout flag with logic, but the problem there is you probably don't always do the same load level, i.e. the "fill" time for the washer varies from load to load. Maybe an alternative logic approach is to "count" or keep track of how many current on cycles you see before the waher is finally finished (wash, rinse, second rinse, then done when no current sensed). Here again this will not work if you vary your patterns (don't do a second rinse?) for all of your loads.
I explained an alternative to this problem HERE (which is the one I presently use).
As far as the washing machine monitored with a current sensor, its going to be difficult because when the machine is filling with water (i.e. no pumps or motors working) it only has a solenoid "on" and draws milliamps of current, which is difficult to monitor with the current line of inductive current sensors. You could try something like a timeout flag with logic, but the problem there is you probably don't always do the same load level, i.e. the "fill" time for the washer varies from load to load. Maybe an alternative logic approach is to "count" or keep track of how many current on cycles you see before the waher is finally finished (wash, rinse, second rinse, then done when no current sensed). Here again this will not work if you vary your patterns (don't do a second rinse?) for all of your loads.
I explained an alternative to this problem HERE (which is the one I presently use).
Having a light on the washer makes the whole thing relatively easy.
This allows you to use the approach I used on the toaster oven and that I've used with washers and dryers before.
You can use a CdS photocell (from Radio Shack, here). The resistance of this device changes with the amount of light striking it. You can build a simple voltage divider using one of these and a resistor - i.e., you can treat this like a variable resistor (potentiometer). You will get a variable voltage which can be used as an input signal to your Ocelot/SECU16. Just tape the photocell over the lamp.
You can test this easily using a multimeter. Stick the photocell on top of the lamp. Measure the resistance with the lamp on and off. You should see a significant difference. You may need to block ambient light to avoid confusing the Ocelot. It all depends on how much the ambient light affects the resistance. You can determine this by trial and error.
Often, the resistance varies enough to allow this to be used as a digital input - the voltage swing is large enough to go above and below the digital cutoff. Otherwise, you can use it as an analog signal.
I've done both. For my toaster, I used a quad comparator (LM339) to compare the voltage with a reference voltage and output a digital signal. For monitoring the washer and drier, I treated it as a digital signal (by the way, the washer/dryer sensor was connected to a wireless doorbell to transmit the status).
If you measure the light on and light off resistances, I'm sure people here can help with the appropriate values to build the voltage divider (if necessary). For all I know, you can connect it directly to the SECU16 - I'm sure Guy can chime in here. If you need to build the divider, you're all set since you recently purchased an assortment of resistors.
By the way, the resistances of these inexpensive CdS photocells can vary quite a bit from one to the other. It's not too unusual to need to use different resistor values when building a voltage divider if you change photocells. For a simple on/off result, you probably don't need to worry about it too much.
This allows you to use the approach I used on the toaster oven and that I've used with washers and dryers before.
You can use a CdS photocell (from Radio Shack, here). The resistance of this device changes with the amount of light striking it. You can build a simple voltage divider using one of these and a resistor - i.e., you can treat this like a variable resistor (potentiometer). You will get a variable voltage which can be used as an input signal to your Ocelot/SECU16. Just tape the photocell over the lamp.
You can test this easily using a multimeter. Stick the photocell on top of the lamp. Measure the resistance with the lamp on and off. You should see a significant difference. You may need to block ambient light to avoid confusing the Ocelot. It all depends on how much the ambient light affects the resistance. You can determine this by trial and error.
Often, the resistance varies enough to allow this to be used as a digital input - the voltage swing is large enough to go above and below the digital cutoff. Otherwise, you can use it as an analog signal.
I've done both. For my toaster, I used a quad comparator (LM339) to compare the voltage with a reference voltage and output a digital signal. For monitoring the washer and drier, I treated it as a digital signal (by the way, the washer/dryer sensor was connected to a wireless doorbell to transmit the status).
If you measure the light on and light off resistances, I'm sure people here can help with the appropriate values to build the voltage divider (if necessary). For all I know, you can connect it directly to the SECU16 - I'm sure Guy can chime in here. If you need to build the divider, you're all set since you recently purchased an assortment of resistors.
By the way, the resistances of these inexpensive CdS photocells can vary quite a bit from one to the other. It's not too unusual to need to use different resistor values when building a voltage divider if you change photocells. For a simple on/off result, you probably don't need to worry about it too much.
BraveSirRobbin
Moderator
Smee, this is an excellent idea and a lot better than the phototransistor idea. I believe E does have a multimeter and we can talk him through this. Thanks for the idea.
Guy Lavoie
Active Member
Actually, the phototransistor would probably be the best solution because of its simplicity. In fact, a photodarlington would be the real thing to use, since you're only looking for on/off conditions here. Photocells are harder to use with low light level sources like pilot lights because they are only resistive and have linear response, so an external circuit like the one smee is mentioning is needed to get it to trigger at a specific light level.
Phototransistors normally have just two leads, and you would connect them directly to a SECU16 input jumpered for supervised mode. No external circuit or power needed. The photodarlington has higher gain so needs less light to trigger, although these are usually found in optoisolators and are rarer as standalone components.
Phototransistors normally have just two leads, and you would connect them directly to a SECU16 input jumpered for supervised mode. No external circuit or power needed. The photodarlington has higher gain so needs less light to trigger, although these are usually found in optoisolators and are rarer as standalone components.
BraveSirRobbin
Moderator
Guy Lavoie
Active Member
BSR, I found this one:
http://jameco.com/webapp/wcs/stores/servle...roductId=120573
which detects visible light. There is not much choice for visible light phototransistors but this one looks good, with a narrow detection angle and lens. The nice thing about this one is that it has a base terminal available, allowing you increase its sensitivity if needed by putting a high value resistor between the base and the supply voltage to forward bias the transistor'a B-E junction somewhat, needing less light to trigger it fully on. Using the base this way would require an external +5v supply but its nice to have the option if the triggering LED or pilot light is not powerful enough. You would need to experiment to be sure.
http://jameco.com/webapp/wcs/stores/servle...roductId=120573
which detects visible light. There is not much choice for visible light phototransistors but this one looks good, with a narrow detection angle and lens. The nice thing about this one is that it has a base terminal available, allowing you increase its sensitivity if needed by putting a high value resistor between the base and the supply voltage to forward bias the transistor'a B-E junction somewhat, needing less light to trigger it fully on. Using the base this way would require an external +5v supply but its nice to have the option if the triggering LED or pilot light is not powerful enough. You would need to experiment to be sure.
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