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DC Power sources for a 1920's Synchronome master & Current Regulation?
Some years ago I made (and still use) some constant current units. The design is from the LM317 application notes. Details attached;
Some years ago I made (and still use) some constant current units. The design is from the LM317 application notes. Details attached;
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John Hubert
· #1179
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DC Power sources for a 1920's Synchronome master & Current Regulation?
The master draws 300 - 350 mA …….. but the duty cycle is low; approximately 100 - 150 mS every 30 seconds, so the average is low. J
The master draws 300 - 350 mA …….. but the duty cycle is low; approximately 100 - 150 mS every 30 seconds, so the average is low. J
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John Hubert
· #1165
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DC Power sources for a 1920's Synchronome master & Current Regulation?
OK, what I actually do is quite different as I have a large system with a distribution board etc. If you have no risk/worry over power cuts, then a ‘wall wart’ type adaptor is fine. If you get power c
OK, what I actually do is quite different as I have a large system with a distribution board etc. If you have no risk/worry over power cuts, then a ‘wall wart’ type adaptor is fine. If you get power c
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John Hubert
· #1163
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Count wheel & backstop roller & Pendulum length to bob?
You will have to try it. It is entirely possible the bob is a replacement, but the weight is not ‘critical’. The rod itself is quite light, so the bob dominates the CoG. You might have to extend the t
You will have to try it. It is entirely possible the bob is a replacement, but the weight is not ‘critical’. The rod itself is quite light, so the bob dominates the CoG. You might have to extend the t
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John Hubert
· #1159
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Count wheel & backstop roller & Pendulum length to bob?
I have just had an (approximate) as they are running measure. Clock No 1 - Lead bob about 16 lbs I believe - fitted with light early type weight tray. Approx 90 cm from top of lower brass suspension b
I have just had an (approximate) as they are running measure. Clock No 1 - Lead bob about 16 lbs I believe - fitted with light early type weight tray. Approx 90 cm from top of lower brass suspension b
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By
John Hubert
· #1157
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Count wheel & backstop roller & Pendulum length to bob?
The ‘notch’ is really a little file cut - and I don’t think it was always used, but I have seen it on some of my clocks. It was not very accurate because things varied. A variety of bob shapes and var
The ‘notch’ is really a little file cut - and I don’t think it was always used, but I have seen it on some of my clocks. It was not very accurate because things varied. A variety of bob shapes and var
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By
John Hubert
· #1154
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Synchronome contacts pitted
Perspex works well and is easy to work. It also looks almost indistinguishable from glass. You can buy a rod of perspex very reasonably and make the rollers in a small lathe. Glass is more difficult,
Perspex works well and is easy to work. It also looks almost indistinguishable from glass. You can buy a rod of perspex very reasonably and make the rollers in a small lathe. Glass is more difficult,
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John Hubert
· #1149
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Count wheel & backstop roller
Glass is correct. I have also used perspex (glass is relatively difficult to drill) with success. The keys to the clock running well are that; The teeth of the count wheel are clean and dry (it runs w
Glass is correct. I have also used perspex (glass is relatively difficult to drill) with success. The keys to the clock running well are that; The teeth of the count wheel are clean and dry (it runs w
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John Hubert
· #1147
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Count wheel & backstop roller
In fact it cannot ‘fall off’ because the K shaped bridge is ‘in the way’. Photo of a slightly earlier clock (which has been running for many years) attached. John
In fact it cannot ‘fall off’ because the K shaped bridge is ‘in the way’. Photo of a slightly earlier clock (which has been running for many years) attached. John
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John Hubert
· #1145
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Synchronome contacts pitted
If you search eBay - there is an un-machined impulse pallet casting listed in the UK. (I am not and have no connection with the seller - nor have I ever seen or examined the part.) John
If you search eBay - there is an un-machined impulse pallet casting listed in the UK. (I am not and have no connection with the seller - nor have I ever seen or examined the part.) John
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John Hubert
· #1143
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Synchronome contacts pitted
For your information, clock 707 would date to about 1919 and would (probably) have originally been in a 'false pediment’ type case, found (mainly) between the approximate serial number range of 680 (a
For your information, clock 707 would date to about 1919 and would (probably) have originally been in a 'false pediment’ type case, found (mainly) between the approximate serial number range of 680 (a
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John Hubert
· #1140
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Synchronome battery life
Howard, your clock would date to circa 1935 - but you probably kew that anyway! John
Howard, your clock would date to circa 1935 - but you probably kew that anyway! John
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By
John Hubert
· #1100
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Synchronome battery life
I can’t comment on power consumption as I run several clocks from a float charged battery (multiple C sized NiMH cells - now about 15 years old) - but 280 mA is on the low side for a Synchronome. 300
I can’t comment on power consumption as I run several clocks from a float charged battery (multiple C sized NiMH cells - now about 15 years old) - but 280 mA is on the low side for a Synchronome. 300
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John Hubert
· #1095
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Master Clock contact spark quenching
Interesting. The Silent Electric (closely related to early GPO clocks) uses make before break and resistors (unknown, but very probably just like the GPO ones). The were designed to work with Silent E
Interesting. The Silent Electric (closely related to early GPO clocks) uses make before break and resistors (unknown, but very probably just like the GPO ones). The were designed to work with Silent E
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John Hubert
· #1089
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Master Clock contact spark quenching
If this is done in the musical world - then I think the assumption that any effect on the timing (i.e. lengthening of coil current duration) is insignificant. In a clock circuit, if you do get the pol
If this is done in the musical world - then I think the assumption that any effect on the timing (i.e. lengthening of coil current duration) is insignificant. In a clock circuit, if you do get the pol
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By
John Hubert
· #1080
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Master Clock contact spark quenching
I do just as you suggest on all my dials and masters. 1N400X series diodes. The maintaining of current is minimal (looked some years ago with an oscilloscope and it was insignificant). There is typica
I do just as you suggest on all my dials and masters. 1N400X series diodes. The maintaining of current is minimal (looked some years ago with an oscilloscope and it was insignificant). There is typica
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John Hubert
· #1078
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Master Clock contact spark quenching
Can anyone explain why we stick with the Synchronome resistor? I can make a few guesses; In a Synchronome, the ‘ON period’ is very short - a few hundred milliseconds per minute, so the losses in a res
Can anyone explain why we stick with the Synchronome resistor? I can make a few guesses; In a Synchronome, the ‘ON period’ is very short - a few hundred milliseconds per minute, so the losses in a res
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By
John Hubert
· #1072
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Synchronome other items
There were a couple of Synchronome ones listed on eBay a year or two back, if I remember rightly, one in a large metal case, the other in a wooden case.
There were a couple of Synchronome ones listed on eBay a year or two back, if I remember rightly, one in a large metal case, the other in a wooden case.
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John Hubert
· #1023
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Show and tell. an electric carriage clock slave.
A bit ‘off topic’, but there are three very good books on ‘Country House Technology’ and lighting; Technology in the Country House by Marylin Palmer & Ian West Country House Technology by P.S. Barnwel
A bit ‘off topic’, but there are three very good books on ‘Country House Technology’ and lighting; Technology in the Country House by Marylin Palmer & Ian West Country House Technology by P.S. Barnwel
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John Hubert
· #997
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Show and tell. an electric carriage clock slave.
There were a number of optional ‘quiet’ designs for 30 second single polarity systems by both Synchronome and Gents - as well as the Silent Electric slaves. Some earlier G&J versions were also rather
There were a number of optional ‘quiet’ designs for 30 second single polarity systems by both Synchronome and Gents - as well as the Silent Electric slaves. Some earlier G&J versions were also rather
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John Hubert
· #993
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