spikes caused by the cooling fans
spikes caused by the cooling fans
(OP)
Hi, everyone:
I'm using a temperature sensor to monitor the temperature of our sample. The temperature reading is shown in my computer. the sensor is powered up by a 12V regular power adapter. It's working OK until I connect a couple of 12V DC cooling fans to the circuit. They are powered up by the same power adapter as the temperature sensor. I observe there are spikes coming up along with the regular temperature reading. For example, the temperature reads room temperature for a while and then all of a sudden it reads 100degreeC, and then come back to the room temperature. I'm wondering if it's the connection of the cooling fans that causes this problem. The cooling fan has two wires. What's the right way to connect the fans into the circuit?
Thanks,
bjbdts
I'm using a temperature sensor to monitor the temperature of our sample. The temperature reading is shown in my computer. the sensor is powered up by a 12V regular power adapter. It's working OK until I connect a couple of 12V DC cooling fans to the circuit. They are powered up by the same power adapter as the temperature sensor. I observe there are spikes coming up along with the regular temperature reading. For example, the temperature reads room temperature for a while and then all of a sudden it reads 100degreeC, and then come back to the room temperature. I'm wondering if it's the connection of the cooling fans that causes this problem. The cooling fan has two wires. What's the right way to connect the fans into the circuit?
Thanks,
bjbdts





RE: spikes caused by the cooling fans
If you have a separate power supply, that would be the best solution. Sensitive instrumentation and motors don't play well together on the same PS.
RE: spikes caused by the cooling fans
Separate the power supplies. Either use separate regulators from a common input or better still use fully independent supplies. Watch your grounding: avoid the power return path from the fans passing through circuit connections which the analogue circuitry uses. A single ground point is often used to avoid shared paths.
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If we learn from our mistakes I'm getting a great education!
RE: spikes caused by the cooling fans
RE: spikes caused by the cooling fans
They can put out some noise. Then you hook two up, they will beat together and possibly cause your wall wart's regulator to lose it.
You should, as others have said, use a separate supply.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: spikes caused by the cooling fans
RE: spikes caused by the cooling fans
Thanks for your responses. I first tried to put a capacitor over 12V power supply. The spikes got smaller and appeared less frequently. Then I tried to use a separate 12V power supply. And it worked! The spikes were gone. Really appreciated your helps.
bjbdts