| Electronics > Beginners |
| Best Overvoltage & Overcurrent Protection forr failproof operation design |
| (1/2) > >> |
| getfast_kiran:
I have the following problem as depicted in Figure 1. I need to provide Over-current & Over-voltage protection. The following circuits are the one I got for over-voltage protection. 1.Using Specialized IC for over-voltage protection 2.Using LM341 and Triac Arrangement. 3.Using a zener and current limiting resistor 4.Using a TVS diode and Fuse(in place of energy absorbing resistor) My load Specs : Load voltage : 5V - 6V Peak Current: 1.5A Continuous Current: 0.25A Can someone guide me how to choose among the above and build a fail-proof over-voltage protection which is cost effective. I really dont want to use the first option since its BGA IC and it is little bit hard to get it soldered ? |
| getfast_kiran:
The load input is given from a Buck converter with specs of 20V to 5V. This is the 5V input that we need to make sure does not go beyond 5V. In a previous implementation the supply jumped from input of buck to the output |
| getfast_kiran:
And when testing the 4th circuit there is good drop in fuse...Could anybody tell me what could be a better way to avoid this drop of about 0.25 to 0.4V. |
| David Hess:
The zener diode and TVS solutions tend to fail with a short which may not be desirable in your application as they would have to be replaced. Usually I see a zener diode used with an SCR or TRIAC but using an LM431 is a good idea for better precision. Capacitance can be added across R2 and the TRIAC shunt resistor to slow response and add noise immunity. The TRIAC can be replaced with an SCR if a PNP bipolar transistor is added between the SCR and LM431 to invert the gate drive signal; it is an extra part but SCRs are less expensive and more rugged. Alternatively a PNP and NPN pair of bipolar transistors can be used in place of the SCR to get the correct gate connection. The TRIAC is the simplest way though. |
| getfast_kiran:
Thanks for helping with this topic. Could you tell me among these which would be the most fail proof among all with no other restriction in both number of parts or cost(reasonable). |
| Navigation |
| Message Index |
| Next page |