Seconds impulse slave clocks with alternating polarity and current driven.<br />These clocks were designed for series connection in a current controlled driver circuit with alternating polarity every second.<br />Drive current may be between 150 and 220 mA.<br /><br />I got two of these clocks kindly given to me by Electromark1, and posted over from the UK to New Zealand to add to my electric master slave clock collection.<br />The clocks were used by the BBC as silent clocks in the studio's and now replaced with newer electronic versions.<br /><br />I designed an simple opto coupler driven circuit which takes pulses of the Gents 1 seconds master clock.<br />The beauty of opto pulses is that there is no burden on the pendulum, as I have lifted the 1 seconds mechanical contacts, this improves clock accuracy as well.<br />An aluminium vane was attached to the pendulum and scanned by two opto heads as can be seen in one of my other video's.<br /><br />I will draw up an exact schema with the LED's in it as well and add a link in the next couple of weeks.<br /><br />Any questions please post here on YouTube and I will do my best to help to resolve any building issues with the electronic components.<br /><br />The parts are easily available from any electronics store, the optocouplers may be a bit harder to get. I got mine from some old ferraris disc utility kWh meters which were discarded at our local powerboard.<br /><br />Parts needed for driver board:<br />Transistors BC547 or 549 x 6<br />Transistors BD 139 x 4<br />Resistors 2k2 Ohms x 4<br />Resistors 470 Ohms x 2<br />Resistors 47k or 100k Ohms x 2<br />Voltage regulator 7812 or LM317 x 1<br />Capacitors 4700uF 16 or 25 Volts x 2<br />Supercap 1 Farad 5.5 Volts<br />LED's optional, some extra series resistors needed ( use 1 k.Ohm for 12 Volts )<br />Piece of veroboard to fit all parts onto<br />12 Volts 500mA dc power supply<br />68 or 82 Ohms 5 Watt ceramic series resistor for clock.
