A EC Fan output a signal 3 pulses per revolution (Isink max = 10 mA), please advise a device to change this signal to on/off signal so that output ON when the Fan is running and OFF when the Fan is not running.
Let me know a specific model would be greatly appreciated because I am green for electronic, thanks!
Thanks crutschow and alec_t, but any relay can do this (close when there has pulse, open when there has no pulse)? the pulse is about 47V, 3 pulses per revolution (Isink max = 10 mA), thanks!
Thanks crutschow and alec_t, but any relay can do this (close when there has pulse, open when there has no pulse)? the pulse is about 47V, 3 pulses per revolution (Isink max = 10 mA), thanks!
If you mean 'can any relay do this?', then no. There are hundreds of pulses per second, and you don't want something that responds to each pulse, but to the string of pulses.
Almost all fan monitors are based on the same circuit, similar to the one Wally posted. If you don't want to build one, you can buy one:
While the OP doesn't specify his location, it seems pretty obvious that English isn't his first language - and he's actually ASKING if it can be done with a relay, rather than stating that it can be.
A EC Fan output a signal 3 pulses per revolution (Isink max = 10 mA), please advise a device to change this signal to on/off signal so that output ON when the Fan is running and OFF when the Fan is not running.
Let me know a specific model would be greatly appreciated because I am green for electronic, thanks!
What is the system Voltage? 12Vdc?
As the fan RPM slows down, at what RPM do you want the output signal to change from ON to OFF?
Is there a requirement to actually use a relay?
What load is the speed detector driving?
We need to know the answer to these questions regardless if you make or buy.
While the OP doesn't specify his location, it seems pretty obvious that English isn't his first language - and he's actually ASKING if it can be done with a relay, rather than stating that it can be.
If you mean 'can any relay do this?', then no. There are hundreds of pulses per second, and you don't want something that responds to each pulse, but to the string of pulses.
Almost all fan monitors are based on the same circuit, similar to the one Wally posted. If you don't want to build one, you can buy one:
What is the system Voltage? 12Vdc?
As the fan RPM slows down, at what RPM do you want the output signal to change from ON to OFF?
Is there a requirement to actually use a relay?
What load is the speed detector driving?
We need to know the answer to these questions regardless if you make or buy.
Thanks MikeMl, zero RPM change to OFF, greater than zero RPM change to ON, power supply for the Fan is 48Vdc, so, I will use a transformer to supply 48Vdc.
According to the spec. of the Fan, it seems output the pulses with 47V.
While the OP doesn't specify his location, it seems pretty obvious that English isn't his first language - and he's actually ASKING if it can be done with a relay, rather than stating that it can be.
What are the manufacturer and the part number for the fan?
Usually a 48V fan has a tach output limited to 12 V or 24 V peak, or an open collector output so you can set your own peak voltage. The tach signal comes from a Hall Effect magnetic field sensor near the motor's rotating magnets, and is good for only around 10 mA. If the tach pulses really are 48 V peak, that is not a problem, just something to address in the circuit. Also, there usually are an even number of pulses per revolution. Are you sure about three?
What kind of "on/off" signal do you need? Does it have to be isolated from the fan power, or have to deliver very much current, or light an LED, or what?
Note that both of those boards are limited to a maximum of 24 V power and 24 V input pulses.
Please ignore Colin's "advice". Simply attaching a relay coil to a power supply will do nothing to monitor the frequency of a low-energy pulsing signal.
What are you saying AnalogKid ????
Please ignore Colin's "advice". Simply attaching a relay coil to a power supply will do nothing to monitor the frequency of a low-energy pulsing signal.
His requirement is:
an output ON when the Fan is running and OFF when the Fan is not running.
What are you saying AnalogKid ????
Please ignore Colin's "advice". Simply attaching a relay coil to a power supply will do nothing to monitor the frequency of a low-energy pulsing signal.
His requirement is:
an output ON when the Fan is running and OFF when the Fan is not running.