| ??? 12/13/08 14:34 Read: times |
#160895 - TVS might blow up Responding to: ???'s previous message |
Erik Malund said:
Oliver Sedlacek said:
Here's an example I used. It's most commonly used on supply rails, but it's applicable to any signal.
 that MAY (I emphasize MAY) work. we have had supplies with this type of crowbar that did not 'kill' the overvoltage fast enough. I would parallel the SCR with a TVS to take the short spike. Erik Oliver Sedlacek said:
The idea is that the exposed side may get connected to 150V,
and the protected side wont get zapped. Eric's comment about "speed of response" is valid, so a zener or TVS may also be required. I assume a blown fuse is preferable to a blown unit, but if replacing fuses is still an issue, you could try a polyswitch resetable fuse (assuming you can get one with a suitable rating). Erik Malund said:
Eric's comment about "speed of response" is valid, so a zener or TVS may also be required
Zeners are too slow Erik 150VDC is a continuous application not a waveform? . A TVS would blow up if the Zener takes time tripping the crowbar . A TVS is only there to stop erratic switching of the Crowbar or am I missing something?. -Ap |
| Topic | Author | Date |
| Protecting supply | 01/01/70 00:00 | |
| Of course there are | 01/01/70 00:00 | |
| info | 01/01/70 00:00 | |
| Crowbar | 01/01/70 00:00 | |
| crowbar | 01/01/70 00:00 | |
| Like this | 01/01/70 00:00 | |
| Short-circuit protection | 01/01/70 00:00 | |
| I like Kai's solution better! | 01/01/70 00:00 | |
| that MAY (I emphasize MAY) work | 01/01/70 00:00 | |
| TVS might blow up | 01/01/70 00:00 | |
| SCR survival! | 01/01/70 00:00 | |
| How attack from both directions? | 01/01/70 00:00 | |
| No nothing is removed | 01/01/70 00:00 | |
| Distributed equipment to protect? | 01/01/70 00:00 | |
| fast response time is necessary | 01/01/70 00:00 | |
| Look at an oscilloscope trigger circuit | 01/01/70 00:00 | |
| and... | 01/01/70 00:00 | |
| Mosfet | 01/01/70 00:00 | |
| The other way round | 01/01/70 00:00 | |
| not a Zener | 01/01/70 00:00 | |
| SCRs are slow! | 01/01/70 00:00 | |
| Zeners are slow! | 01/01/70 00:00 | |
| Slow? | 01/01/70 00:00 | |
| Try to convince the mechancis by arguing... | 01/01/70 00:00 | |
| Nice grip... | 01/01/70 00:00 | |
Maybe you can reverse the damage | 01/01/70 00:00 |