Q&A(FAQ) What does "Open collector" means?
Some COSEL power supplies are equipped with an alarm function.
A representative type of alarm output is the open-collector method, which outputs a signal to detect various internal operating conditions of the power supply.
When the alarm output terminal uses the open-collector method, it does not output a specific voltage or current as a signal. Instead, it uses an NPN transistor as a switch to represent the output state.
When using this terminal, please supply the collector terminal with an external power source voltage.
Additionally, please install a current-limiting resistor to ensure that the current does not exceed the value specified in the instruction manual.
The time required for the alarm signal to become “High” varies depending on the model and operating conditions. Please be aware of this.
In addition, the alarm signal may be isolated from other circuits (such as input, output, FG, and RC), or it may not be isolated, depending on the product. For details, please refer to the instruction manual of each model.
Some products provide an AUX output that can be used as an external voltage source. The output current drawn from the AUX terminal must remain within its rated current.