Got adjustable power supply and ammeter to "Tiny Cooling Fan" relay input a set of voltage and power supply circuit in series with an ammeter to monitor. Slowly increase the supply voltage, relay pull hear the sound a note of the pull-in voltage and pull current. For accuracy, you can try more than a few times and averaged. Measuring the release voltage and current is also releasing the connection test as described above, when the "Tiny Cooling Fan" relay happen pull, and then gradually reduce the supply voltage, relay release occurs when they heard the sound again, note the time of the voltage and current, and also try to get more than a few average release voltage and current release. Under normal circumstances, the release voltage "Tiny Cooling Fan" relay pull in about 10 to 50% of the voltage, if the release voltage is too small (less than 1/10 of the pull-in voltage), you can not normally use, this will be the circuit pose a threat to the stability of the work is not reliable. Edit this paragraph electrical symbols and Contact Form