2
\$\begingroup\$

I have a benchtop power supply (it's not in front of me right now, so I can't say the model, sorry) and it has a current limiting mode enabling it to operate as a current source. However, it also has an "over-voltage" and "over-current" protection mode (OVP and OCP, respectively). Once either OVP or OCP trip, the supply stops providing any power.

My question is: why do those protection modes exist if I can just set the limits on current and voltage myself? Presumably, if I know what to set the protection modes to I'll know what to set the limits to, so what's the point?

\$\endgroup\$
  • \$\begingroup\$ No. It turns out I can just google image search and find it :-P It's a Keysight U8002A \$\endgroup\$ – Michael Stachowsky Jan 25 '18 at 11:45
  • \$\begingroup\$ In some situations you want it to behave one way, in some the other. \$\endgroup\$ – PlasmaHH Jan 25 '18 at 11:48
  • \$\begingroup\$ I can imagine, yes. What might an example be of a situation in which CC mode is insufficient? \$\endgroup\$ – Michael Stachowsky Jan 25 '18 at 11:50
  • \$\begingroup\$ OCP might be operating on the input supply feed? \$\endgroup\$ – Andy aka Jan 25 '18 at 11:51
  • 1
    \$\begingroup\$ @MichaelStachowsky: I would probably not enable it if possible, or set it to somewhat higher. \$\endgroup\$ – PlasmaHH Jan 25 '18 at 11:56
2
\$\begingroup\$
  • OVP - OverVoltage Protection: When OVP function is turned on, if the output voltage is higher than protection setup value, the output cuts off - ie. goes to 0V.
  • CC - Constant Current mode: When the power supply is in constant current mode, it will limit the output to voltage that gives the setup current value through the load.
  • OCP - OverCurrent Protection: When over current function is turned on, if the output current is higher than protection setup value, the output cuts off - ie. goes to 0V.
\$\endgroup\$
2
\$\begingroup\$

With a bench power supply you also have to take account for what the thing is attached to.

The CC circuit may be set to say 3A, but if the circuit is back-feeding, or through-feeding 5A the CC won't protect you.

Same goes for voltage, You may set the adjuster to hold 12V but if the output is shorted to 24V you want the bench power supply to let go.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.