[GreenKeys] Lamp for ASR33

[Jack]

Mike,

 

Just be careful with the heat from the LED’s. I had seen mods in the past

that used a small fluorescent lamp that eventually melted the cover.

 

Jack K2TTY

 

 

 

 

 

From: GreenKeys [mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of Michael Zahorik
Sent: Monday, April 10, 2017 7:17 PM
To: greenkeys at mailman.qth.net
Subject: [GreenKeys] Lamp for ASR33

 

A couple of weeks ago I asked about a lamp that illuminates the typing on a ASR33 TTY. Apparently there was no such thing. So, I found a LED strip that I Velcro'ed to the underside of the cover. I connected the LED's to the 48 volt supply through a full wave bridge, filter cap and a dropping resistor. This LED has 36 LED's and is rated at 200 ma, but that is way way too bright. I cut it down to 70 ma and this is plenty bright. These pictures are not the best, but I'm pleased with the results. It is now easy to see what is being typed.

 

Mike Zahorik (414) 254-6768

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