Help with identifying what diode to use in car battery tester circuit

[Ev47487]

Hi, I'm trying to build the circuit from the following link CIRCUIT2
It is the 3rd one down called Car Battery Tester.
Towards the right of the circuit is a diode with part no. BYV90, but I think this may incorrect as I cannot find anyone who lists it! Can anyone suggest a suitable alternative?
Thanks
Evan.

 

[#12]

That looks like a "fuse blower" to me. All it does is take out the fuse if you connect the battery backwards. Using a 2 amp fast fuse would probably make it OK to use a 3 amp power rectifier. 1N540, maybe.

Anybody on this site is allowed to correct me! I'm not sure how to rate a diode for intentional fuse blowing.

 

[Ev47487]

Thanks very much for your reply. I can get on and buy the rest of the bits now, I'll set up a few 1n4007 1Amp Diodes (which I've got lots of) in parallel as a substitute. Thanks again. Evan.

 

[#12]

Good! I think I should have typed 1N5401. Just make sure you use a standard fuse, not a slo-blow.

 

[4pyros]

Yes that is a reverse polarity protector. you can leave it out for testing and use any fast 2amp or bigger diode. It should be right after the fuse whare the power comes in not at the end as shown in the schematic. Andy