Output On/Off Behaviour of PBZ Series

Posted on: June 23rd, 2021 by Doug Lovell

For PBZ Series, a magnetic relay is used to turn the output on/off. The relay is off to turn the output off; when the output is off, the output is in the high impedance state.
In addition, if the output-on/off is controlled by an external signal input, the embedded firmware in PBZ may cause a jitter on the output voltage.
Now we are going to focus on the following two topics of the output on/off behaviour of PBZ and explain how:
1. the output voltage and output impedance change during the output on/off operation
2. PBZ responses to the output-on/off external signal input.

1. Change in Output Voltage and Output Impedance during Output-On/Off Operation
Figure 1 shows: change in the output voltage (Vout) and output impedance when the output is turned on. Figure 2 shows: change in Vout and output impedance when the output is turned off.
* The rise and fall time of Vout is dependent on the response setting by PBZ.

1-1. Output On

1-2. Output Off

Output Impedance:
・ PBZ20-20: 120 kΩ ・ PBZ40-10: 220 kΩ ・ PBZ60-6.7: 320 kΩ ・ PBZ80-5: 420 kΩ Low:
・ a few hundred Ω Very Low:
・ Output is turned on.

1-3. Recommended Method to Frequently Turn Output On/Off
If you want to repeatedly switch the output on/off over a long period of time, we recommend the following procedures to prolong the lifetime of the relay:
1. Keep the output on.
2. To turn the output off, set the output voltage (Vset) to 0 V.
For DC output only: If you want to set the high impedance when the output is off, place a diode in series with the output terminal of PBZ and set Vset to 0 V.
* For the battery charging application, also place a diode in series with the output terminal of PBZ.
2. Output-On/Off Response to External Signal
In Figure 3 and 4, you can find the jitters when the output is turned on/off via the external signal input: ● Signal lag for output-on: approx. 90 ms max.
● Signal lag for output-off: approx. 50 ms max. ● Jitter during output-on/off: approx. 45 ms
In Figure 4, the lag between the output-off signal input and when the output impedance becomes high is approx. 90 ms max. and the jitter is approx. 45 ms; this lag is 50 ms min. and 90 ms max.
2-1. Output On

2-2. Output Off

Products Mentioned In This Article:

PBZ Series please see HERE