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DEC RL02 indicator bulbs - UK source ?

Z

zippysticks

Veteran Member
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Nov 21, 2017
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UK, South East
Folks,

anyone know of a source for these small bulbs that pop into the indicator lights/switches of the RL02 drive please ?

#74 Sub Miniature Wedge Base Bulb.- T-13/4 Type - 14.0V.10A

I see Element14/Farnell have them in the USA but I can't find a UK source.

Are there any LED alternatives these days ?

Thanks
 
zippysticks said:
anyone know of a source for these small bulbs that pop into the indicator lights/switches of the RL02 drive please ?

#74 Sub Miniature Wedge Base Bulb.- T-13/4 Type - 14.0V.10A

I see Element14/Farnell have them in the USA but I can't find a UK source.

Are there any LED alternatives these days ?
Click to expand...
The schematic
http://www.bitsavers.org/pdf/dec/disc/rl01_rl02/MP00553_RL02_RevB_Engineering_Drawings_Nov79.pdf

says they are GE 73 type. I see some on ebay that say T-1 3/4 type, but I'm in the US. You'll probably see different sellers when searching from the UK.

1688238061028.png

I looked because you mentioned an LED alternative. I used this small, bright, 2700K LED

TJ-S3528UG6W9TLC3DW-A5 TOGIALED | C440445 - LCSC Electronics

TJ-S3528UG6W9TLC3DW-A5 TOGIALED US$0.0339 - 2700K~3300K -40℃~+80℃ White light 120° 108mW SMD3528 Light Emitting Diodes (LED) ROHS datasheet, price, inventory C440445
www.lcsc.com www.lcsc.com
in the RK05 emulator that maybe could be used in a GE 73 replacement circuit. If you're inclined to build something like this, the LED, a tiny bridge rectifier (so the LED-equivalent has no polarity) and a current limiting resistor might be all you'd need. I notice the RL02 connects the lamps between +5V and -8V, and there's a 470 ohm keep-alive resistor, so an LED equivalent circuit would need to consider that.

For my taste I'd prefer the real lamp to be more like the vintage device.
 
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zippysticks said:
Folks,

anyone know of a source for these small bulbs that pop into the indicator lights/switches of the RL02 drive please ?

#74 Sub Miniature Wedge Base Bulb.- T-13/4 Type - 14.0V.10A

I see Element14/Farnell have them in the USA but I can't find a UK source.

Are there any LED alternatives these days ?

Thanks
Click to expand...
These are a very commonly used automotive bulbs (dashboards, etc) with older vehicles... I bought them in-bulk from rockauto.com over here (24 bulbs for $20, yes - I have MANY RL01/02 drives!). I'd imagine that any autoparts supplier over there would have lots of these bulbs in-stock.

Type #73 for RL01/02 drives and Type #86 for RA8x drives.

A bulb-test can easily be accomplished by powering-on the drive not connected to the controller:
1688243282441.png

Also, I have a bunch of extras:
image.png

-Chris
 
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