Home |
Search |
Today's Posts |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
|
|||
|
|||
Heathkit Question
Hi all,
I have a quick question I was wondering if someone might be able to answer. What is the standard light bulb number for the 5V lamps in a Heathkit GC-1195/1197 clock. They are 5V miniature wedge type light bulbs that are used for the display segments. I guess this could be a proprietary Heathkit part, but I was hoping maybe someone had changed these and maybe knew if there was a standard bulb equivalent (the Heathkit part number is 412-621. Thanks and I do appreciate any help. Ralph Farr |
#2
|
|||
|
|||
Heathkit Question
What you should do is see if you can get a Newark or equivalent catalogue
and carefully go through it. There are hundreds of different types of these small lamps. I am sure that your lamps are of some standard. I doubt very much that Heath had their own made, especially in the time that they were around. If there are any electronic suppliers in your area, which you can check to verify in your yellow pages, pay them a visit with a sample of a lamp. You can try Radio Shack, or a TV service place, but these would be very limited. If you know the voltage and current rating of the lamp, you can probably substitute it and also install new sockets to match. This is too much of a hassle for something that is standard. -- Greetings, Jerry Greenberg GLG Technologies GLG ========================================= WebPage http://www.zoom-one.com Electronics http://www.zoom-one.com/electron.htm ========================================= "Ralph Farr" wrote in message ... Hi all, I have a quick question I was wondering if someone might be able to answer. What is the standard light bulb number for the 5V lamps in a Heathkit GC-1195/1197 clock. They are 5V miniature wedge type light bulbs that are used for the display segments. I guess this could be a proprietary Heathkit part, but I was hoping maybe someone had changed these and maybe knew if there was a standard bulb equivalent (the Heathkit part number is 412-621. Thanks and I do appreciate any help. Ralph Farr |
#3
|
|||
|
|||
Heathkit Question
They sound like a standard wedge base 5v lamp. Can you scan or photo this,
and I will match. Kim "Ralph Farr" wrote in message ... Hi all, I have a quick question I was wondering if someone might be able to answer. What is the standard light bulb number for the 5V lamps in a Heathkit GC-1195/1197 clock. They are 5V miniature wedge type light bulbs that are used for the display segments. I guess this could be a proprietary Heathkit part, but I was hoping maybe someone had changed these and maybe knew if there was a standard bulb equivalent (the Heathkit part number is 412-621. Thanks and I do appreciate any help. Ralph Farr |
#4
|
|||
|
|||
Heathkit Question
Ralph Farr wrote in message ...
Hi all, I have a quick question I was wondering if someone might be able to answer. What is the standard light bulb number for the 5V lamps in a Heathkit GC-1195/1197 clock. They are 5V miniature wedge type light bulbs that are used for the display segments. I guess this could be a proprietary Heathkit part, but I was hoping maybe someone had changed these and maybe knew if there was a standard bulb equivalent (the Heathkit part number is 412-621. Thanks and I do appreciate any help. Ralph Farr Hi Ralf, I built one of those clocks a long time ago and it is currently lounging on my "to play with" pile. It was a great conversation piece, and always drew comments. Those little bulbs are problematic. I've had the clock for years and they get loose in the socket, or burn out at different times. I'm planning on replacing them with high brightness L.E.D.'s. You could measure the lamp voltage with the photocell light (I think I remember the intensity increasing with room light) and calculate an appropriate value of series resistance for the LED. Glue it into the segment, wire it to the board with soldered connections and you are done for probably a few decades. I did illuminate a segment red, and it looked great (keep the LED at the back of the bulb hole so the segment can spread the light). I'd love to see it in blue, but then you get pretty expensive. Illuminate a segment for yourself with a LED before you commit to hacking it up. If you use multiple LEDs per segment, I'm sure you can make the thing overly bright. As I said, it is waiting for me to try and I have no final report. For me, if it doesn't work out, I'll trash the clock anyway. I'm done playing bulb-boy. That clock used to throw off some warmth from the linear regulator. This should save some power as well. Now, if you could only add the "atomic clock" circuit so the thing sets its own time on power outage... Good Luck, Jim |
#6
|
|||
|
|||
Heathkit Question
Thanks for your reply Jim - I had never thought about using LED's but that is something I would definitely consider now. Ralph Seems it would kinda lose some of it's vintage charm if you did that, incandescent segments are something you don't see much these days. |
#7
|
|||
|
|||
Heathkit Question
Yeah, and the reason you don't SEE many of them any more is that they keep
burning out! Perhaps the way to keep the vintage stuff original would be to put a small value resistor in series with the bulbs so they last longer. They'd be dimmer, but put it on a shelf near the ceiling where it's darker anyway and maybe no one will notice. Bob M. ====== "James Sweet" wrote in message news:Rbyqb.131661$Tr4.337858@attbi_s03... Thanks for your reply Jim - I had never thought about using LED's but that is something I would definitely consider now. Ralph Seems it would kinda lose some of it's vintage charm if you did that, incandescent segments are something you don't see much these days. |
#8
|
|||
|
|||
Heathkit Question
"Bob M." wrote in message ... Yeah, and the reason you don't SEE many of them any more is that they keep burning out! Perhaps the way to keep the vintage stuff original would be to put a small value resistor in series with the bulbs so they last longer. They'd be dimmer, but put it on a shelf near the ceiling where it's darker anyway and maybe no one will notice. Bob M. Well yeah, I didn't say incandecent was very practical, but it's cool none the less. Someone else mentioned this unit has a photocell to dim it when the room is dark, one could probably just put a variable resistor across or in series with this to adjust the max brightness, dimming it 20% would extend lamp life considerably, but then if you get a large quantity of replacement lamps it'd be pretty easy to just replace them when they burn out, or group relamp the segments that see the most use. |
#9
|
|||
|
|||
Heathkit Question
Hi
You can go a long way to drive the life of the bulb up with two resistors. Put one resistor in series with the bulb to knock down the applied voltage. The other resistor is put in parallel across the switch to put just a little current through the filament when it is supposed to be off. It should just glow faint red. By doing this, the inrush current is reduced since the filament is already hot. Inrush current is what kills the bulbs. Regards "James Sweet" wrote in news:8tBqb.132610$Tr4.339531@attbi_s03: "Bob M." wrote in message ... Yeah, and the reason you don't SEE many of them any more is that they keep burning out! Perhaps the way to keep the vintage stuff original would be to put a small value resistor in series with the bulbs so they last longer. They'd be dimmer, but put it on a shelf near the ceiling where it's darker anyway and maybe no one will notice. Bob M. Well yeah, I didn't say incandecent was very practical, but it's cool none the less. Someone else mentioned this unit has a photocell to dim it when the room is dark, one could probably just put a variable resistor across or in series with this to adjust the max brightness, dimming it 20% would extend lamp life considerably, but then if you get a large quantity of replacement lamps it'd be pretty easy to just replace them when they burn out, or group relamp the segments that see the most use. |
#10
|
|||
|
|||
Heathkit Question
Ralph Farr wrote in message
Thanks for your reply Jim - I had never thought about using LED's but that is something I would definitely consider now. Ralph Sorry on the mis-type of your name. The control chip is, apparently, National MM5387AA/N Can't vouch for the source, but here you go: http://www.chipdocs.com/pndecoder/da...MM5387AAN.html Jim |
#11
|
|||
|
|||
Heathkit Question
Ralph Farr wrote in message
Thanks for your reply Jim - I had never thought about using LED's but that is something I would definitely consider now. Ralph Sorry on the mis-type of your name. The control chip is, apparently, National MM5387AA/N Can't vouch for the source, but here you go: http://www.chipdocs.com/pndecoder/da...MM5387AAN.html Jim |
#12
|
|||
|
|||
Heathkit Question
Random Electron wrote:
Hi You can go a long way to drive the life of the bulb up with two resistors. Put one resistor in series with the bulb to knock down the applied voltage. The other resistor is put in parallel across the switch to put just a little current through the filament when it is supposed to be off. It should just glow faint red. By doing this, the inrush current is reduced since the filament is already hot. Inrush current is what kills the bulbs. I did something like this once... I'd been playing around with LM3915 bargraph display chips, and after getting some LEDs going, I wanted to use incandescent bulbs. So I built a driver board, and across each switching transistor I put a 100 ohm resistor. When the power was on you could just *barely* see the filament glowing. Never had a bulb burn out, either. (These were #47 bulbs, for whatever that's worth.) |
#14
|
|||
|
|||
Heathkit Question
"James Sweet" wrote in message news:Rbyqb.131661$Tr4.337858@attbi_s03...
Thanks for your reply Jim - I had never thought about using LED's but that is something I would definitely consider now. Ralph Seems it would kinda lose some of it's vintage charm if you did that, incandescent segments are something you don't see much these days. Hi James, I read the Heathkit circuit description and it basically says the full lamp voltage is 5 volts regulated and will dim from there. So if you want to keep it vintage, I would look into Chicago Miniature lamp #86 available from 'www.mouser.com' as p/n 606-CM86, they are T1-3/4 wedge base at 6.3 volts rated 20,000 hrs. That seems to indicate that they will last over 2 years. In my experience, whenever anyone commented on the clock and I said I had built it, the next minute the time was in Klingon (When all were looking, of course). The sockets seem to be problematic as well, many times I opened it to relamp, and it was just the way the segment was pushing on the bulb. In my opinion it is a poor and frustrating design. Sorry I didn't post the p/n right away, but I actually had to open the clock and measure the bulb. I'm lousy at judging dimensions. LED's, that's for me! This thread is going to make me break out the soldering iron. I have a few "white" led's that could be tried. I guess if you get the vintage color that you like the only difference would be that the LEDs may turn on and off more abruptly. You could probably ramp the voltage on the flashing colon to make this unnoticeable. For some real fun put an RGB tri-color LED and drive circuit in. You could probaly match the color of the lamps then. See http://www.superbrightleds.com/TriColor%20LED.htm You could program it to randomly change colors every 5 minutes. Now that would be a conversation piece! It would look great right next to the lava lamp. Burn some incense, put on your John McLaughlin albums (you know, the big black CD's). Let people worry about your sanity, maybe a vacation will be suggested! Regards, Jim |
#15
|
|||
|
|||
Heathkit Question
In article ,
says... "James Sweet" wrote in message news:Rbyqb.131661$Tr4.337858@attbi_s03... Thanks for your reply Jim - I had never thought about using LED's but that is something I would definitely consider now. Ralph Seems it would kinda lose some of it's vintage charm if you did that, incandescent segments are something you don't see much these days. Hi James, I read the Heathkit circuit description and it basically says the full lamp voltage is 5 volts regulated and will dim from there. So if you want to keep it vintage, I would look into Chicago Miniature lamp #86 available from 'www.mouser.com' as p/n 606-CM86, they are T1-3/4 wedge base at 6.3 volts rated 20,000 hrs. That seems to indicate that they will last over 2 years. In my experience, whenever anyone commented on the clock and I said I had built it, the next minute the time was in Klingon (When all were looking, of course). The sockets seem to be problematic as well, many times I opened it to relamp, and it was just the way the segment was pushing on the bulb. In my opinion it is a poor and frustrating design. Sorry I didn't post the p/n right away, but I actually had to open the clock and measure the bulb. I'm lousy at judging dimensions. LED's, that's for me! This thread is going to make me break out the soldering iron. I have a few "white" led's that could be tried. I guess if you get the vintage color that you like the only difference would be that the LEDs may turn on and off more abruptly. You could probably ramp the voltage on the flashing colon to make this unnoticeable. For some real fun put an RGB tri-color LED and drive circuit in. You could probaly match the color of the lamps then. See http://www.superbrightleds.com/TriColor%20LED.htm You could program it to randomly change colors every 5 minutes. Now that would be a conversation piece! It would look great right next to the lava lamp. Burn some incense, put on your John McLaughlin albums (you know, the big black CD's). Let people worry about your sanity, maybe a vacation will be suggested! Regards, Thanks Jim for actually opening up the clock and checking out the bulb for me - I didn't mean for you to go to that much trouble! I really do appreciate it though. Are these the ratings for the original heathkit lamps - 6.3V .2A or is the original no longer produced? I was just wondering since the clock outputs 5V to the bulbs - I guess that was to dim the output a little and possible prolong bulb life. Thanks again for your help. Ralph |
#16
|
|||
|
|||
Heathkit Question
"Ralph Farr" wrote in message ... In article , says... Ralph Farr wrote in message Thanks for your reply Jim - I had never thought about using LED's but that is something I would definitely consider now. Ralph Sorry on the mis-type of your name. The control chip is, apparently, National MM5387AA/N Can't vouch for the source, but here you go: http://www.chipdocs.com/pndecoder/da...MM5387AAN.html Jim Thanks everyone for the replies - it has been a very interesting discussion. I do like the vintage light bulb segments, but it would be great to improve reliability. I was thinking about possibly using clear white LED's to replace the bulbs. I haven't worked with any white light emitting LED's - are there any as bright as a miniature incandescentt lamp or would it take several to equal the same brightness? They're quiet bright, but generally in a rather tight beam, also they have a much higher color temperature, they look more like fluorescent light. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
ACID QUESTION | Metalworking | |||
OT - Norstar 3x8 phone system question | Metalworking | |||
chemistry question | Metalworking | |||
Pushfit plumbing question | UK diy | |||
Pipe thread question, NPT vs NPSF, MIP, FIP and IPS | Metalworking |