Note: The Vernier Current Probe is limited to 0.6A maximum. The probe will be destroyed if overloaded, and these probes cannot be repaired. To make sure that students do not ruin the probes, always use this power supply in a current-limited mode. There are two ways to do this:
The No-Brainer Method
- This technique limits the maximum current to 0.200A, which is well below the 0.600A limit of the current probe.
- Make sure the HI–LO range selector is set on LO.
- With the power supply off, zero all of the control knobs to the left (anti–clockwise).
- Adjust only the fine control of the current to maximum (clockwise). The coarse control of the current remains at zero.
- When you switch the power supply on, you will adjust only the voltage to power your circuit.
The Instek User's Manual Method
- Determine the maximum safe current for the device to be powered (in this case, 0.500A, just to be on the safe side).
- Temporarily short the (+) and (-) terminals of the power supply together with a test lead.
- Rotate the COARSE VOLTAGE control away from zero sufficiently to have the CC indicator lightened.
- Adjust the CURRENT control for the desired current limit. Read the current value on the Ammeter.
- The current limit (overload protection) has now been preset. Do not change the CURRENT control setting after this step.
- Remove the short between the (+) and (-) terminals and hook up for constant voltage operation.