hpotter Posted March 10, 2009 Share Posted March 10, 2009 The CPA6 was also my first foray into eol wiring, bit before it's time. Me too.. It was fun fault finding on them. Steep learning curve. (I was still servicing some systems with end of line batts at the time n thought "this is the future"). Link to comment Share on other sites More sharing options...
lawandorder Posted March 10, 2009 Share Posted March 10, 2009 Me too.. It was fun fault finding on them. Steep learning curve. (I was still servicing some systems with end of line batts at the time n thought "this is the future"). Blimey, how old are you? lol End of line batteries are before even my time! I wonder who it was that thought "hang on, why don't we just use four core then we can put the end of line batteries in the panel. (metaphrically speaking) Link to comment Share on other sites More sharing options...
hpotter Posted March 10, 2009 Share Posted March 10, 2009 Blimey, how old are you? lolEnd of line batteries are before even my time! I wonder who it was that thought "hang on, why don't we just use four core then we can put the end of line batteries in the panel. (metaphrically speaking) LOL. Said servicing - not fitting!! 2 x 1.5v flag cells in a box, 1 leg earth, 1 wire back to a slugged relay. Wern't even a pair of wires! I even serviced a "record player" - rubber band, needle on record, solenoid let go of rubber band on trigger and "played" recorded message down line. Them days was - local bells, remote bells (down nick) & voice to operator. No not old, 25 next month. Link to comment Share on other sites More sharing options...
lawandorder Posted March 10, 2009 Share Posted March 10, 2009 LOL. Said servicing - not fitting!!2 x 1.5v flag cells in a box, 1 leg earth, 1 wire back to a slugged relay. Wern't even a pair of wires! I even serviced a "record player" - rubber band, needle on record, solenoid let go of rubber band on trigger and "played" recorded message down line. Them days was - local bells, remote bells (down nick) & voice to operator. No not old, 25 next month. 25? I must admit you have seen a lot for your age, I started working with alarms when I was 17 in 1980 (roughly) and although I have seen record players (and removed a few) my earliest installs were 999ers with 8 track cartridges. Also worked a lot on private wires (direct line to the local nick), in fact it was my job to remove our home office panels from all the nicks on my patch when they became redundant (about 1987 I'm guessing). Do you remeber the havoc that was caused when a Post Office engineer reversed a pair not realising it was a private wire? lol Link to comment Share on other sites More sharing options...
james.wilson Posted March 10, 2009 Share Posted March 10, 2009 never seen an eol cell. Never worked on a private wire. and im well old at 32 securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount. Link to comment Share on other sites More sharing options...
lawandorder Posted March 10, 2009 Share Posted March 10, 2009 never seen an eol cell. Never worked on a private wire. and im well old at 32 Most engineers probably haven't and to be honest things are much better now but it is interesting to understand how EOL cells worked. Many really old systems had flag cells at the end of a length of bell wire, at the other end of the wire was a relay so the relay was powered permanently by the cells. If the wire was broken (by a door contact eg) the realy would open because power is interrupted, if the wire was shorted (tamper or pressure mat) again the realy would open. In a sense this is pretty much how modern (double pole) wiring works except nowdays four cores are used and the power is provided at the panel. Private wires used a very simple 2 transistor oscillator to send a tone down the wire to the home office panel in the nick, cutting the wires, shorting the wires or reversing them caused a line fault to show at the police station (which was often ignored). When a full activation occured a DC signal was sent down the wire causing an alarm to register (this was also often ignored unless you did by accident during a routine call in which case you got a rollicking from the desk seargent) Link to comment Share on other sites More sharing options...
james.wilson Posted March 10, 2009 Share Posted March 10, 2009 that is a proper 'suck eggs' post aint it James securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount. Link to comment Share on other sites More sharing options...
lawandorder Posted March 10, 2009 Share Posted March 10, 2009 that is a proper 'suck eggs' post aint it James Is it? It wasn't meant to be, just that a lot of engineers that I speak to don't have a lot of exposure to really early stuff and many of them do show an interest in how the early security systems influenced the stuff we use today. Link to comment Share on other sites More sharing options...
Guest old-hand Posted March 10, 2009 Share Posted March 10, 2009 that is a proper 'suck eggs' post aint it James Yeah but you aint lived till you service a Link to comment Share on other sites More sharing options...
james.wilson Posted March 10, 2009 Share Posted March 10, 2009 only? securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount. Link to comment Share on other sites More sharing options...
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