MPS-U45 / CEN-U45 transistor alternatives

[BallyWilliams suck]

Hi all.

Gottlieb system 1 and 80 driver boards use a obsolete transistor. I’ve read that a suitable replacement would be a bd679 if the legs are swapped. Some people are suggesting the use of a tip102, where others are saying not to.

Can anyone suggest a suitable alternative? Happy to bend legs - so it doesn’t have to be a direct replacement….

Thanks!

 

[drhex]

Quick look, a NTE272 should be the same -pin out may be different.

 

[BallyWilliams suck]

Unfortunately, those are just as obsolete. Prices are around £25 each!

 

[pinballmania]

https://www.mouser.co.uk/ProductDetail/Central-Semiconductor/CEN-U45-PBFREE?qs=u16ybLDytRYEmAHvoJtMTA%3D%3D

 

[BallyWilliams suck]

Thanks guys. I had seen those - just assumed there would be another alternative for a few pence by now ….!

 

[AlanJ]

what’s wrong with using a tip122 or 102?

 

[BallyWilliams suck]

From what I've read, it's not possible.

The DC current gain of a MPS-U45 is much higher and thats why you can drive them directly with a TTL output. It isn't capable of driving a TIP102 into saturation, and it doesn't get fully switched. The lamp or coil isn't fully driven and the transistor can get hot, and burn....

 

[Moonraker]

It looks like Big Daddy are using 2N6043.

Available from RS https://uk.rs-online.com/web/p/bipolar-transistors/1844152

 

[BallyWilliams suck]

Thanks - I've just had a quick look. The kits they are supplying use the cen-u45. The 2N6043 are for the other transistors used on the board....

 

[Moonraker]

My bad, I miss-understood his American way of saying the ones showing in the photo should be 2N6043 and not CEN-U45 that are pictured.