Categories

App note: Automotive power circuit handles interruptions and 72volt spikes

Posted on Saturday, June 4th, 2011 in app notes by Ian

rsdio writes:  More good ideas to steal and repurpose

This circuit maintains power to the load regardless of momentary shorts or opens in the supply voltage, and includes a low-current overvoltage-protection IC (MAX6495) that protects the load against transient voltages up to 72V.

This entry was posted on Saturday, June 4th, 2011 at 12:23 pm and is filed under app notes. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

4 Responses to “App note: Automotive power circuit handles interruptions and 72volt spikes”

  1. Paul says:

    Q1 & Q2 are opposite polarity, but have the same part number. Likewise for Q3 & Q4. Hmmm…

  2. Token says:

    Would this still require a Schottkey diode for reverse voltage protection?

  3. rsdio says:

    I don’t think you necessarily need a Schottky for reverse-voltage protection – any diode should do. The Schottky has a low forward-voltage drop, but there are other LDO diodes out there.

    If there is a chance that the input will have reverse polarity, then you should check the MAX6495 data sheet for voltage tolerance on the pin 1 input. Q1 and Q3 should handle negative voltages, but I can’t be sure without checking their data sheets, too.

Leave a Reply

Notify me of followup comments via e-mail. You can also subscribe without commenting.

Recent Comments

  • Edward Mallon: I've managed to get cheap thermistors calibrated to about to +/- 0.2C with 3.3v Arduinos. https://edwardmallon.wordpress.com/2017/04/26/calibrating-oversampled-thermistors-with-an-arduino/ Instead of playing whack-a-mole with the various sources of...
  • Ja: What the keyer do? Sends random morse code or there is some input? If someone can point me to some source to read I would...
  • Sorin: Pleasure of free!
  • hli: Sunday++
  • Max: Jolly good stuff, although the "include 100 W resistors in series with the inputs and outputs" part is quite hilarious until one realizes* they meant...