Transistor balanced wheel clock driving circuit

Thread Starter

ranatungawk

Joined Oct 30, 2008
188
These two are driving-circuits of Old Transistor balanced wheel clocks. As below, there are two type of circuits. Could you please explain me what is the purpose of resister “X” .. why two type of arrangement ? what is the most effective circuit ?

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1653464787496.png 1653464813870.png
 

Dodgydave

Joined Jun 22, 2012
10,306
In number 1 the resistor biases the transistor directly from the battery supply, so it's quicker to turn on , whereas in number 2 it's connected through the coils, so the back emf will switch it off faster , i would say number 2 is the best circuit.
 
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Thread Starter

ranatungawk

Joined Oct 30, 2008
188
In number 1 the resistor biases the transistor directly from the battery supply, so it's easier to turn on , whereas in number 2 it's connected through the coils, so the back emf will switch it off faster , i would say number 2 is the best circuit.
Thanks for the information:

in both cases, Is the swing of the balanced wheel same ?
 

Ya’akov

Joined Jan 27, 2019
5,660
I am guessing that the choice of circuit might matter depending on the construction of the wheel. One would “kick“ the wheel harder, the other let go more suddenly.
 

sparky 1

Joined Nov 3, 2018
717
The RLC oscillator circuit shown is simplistic and unregulated relying on the imagination to be a balanced wheel
for driving a clock that one would assume the mechanical clocks are somehow related.
 

Thread Starter

ranatungawk

Joined Oct 30, 2008
188
The RLC oscillator circuit shown is simplistic and unregulated relying on the imagination to be a balanced wheel
for driving a clock that one would assume the mechanical clocks are somehow related.
This is correct ! even here, it runs a little fast or a little slow without any interference.
 

AlbertHall

Joined Jun 4, 2014
12,023
Does the kick attract the magnet or repel it? --- Don't both are same ???
In one case the approach of the magnet towards the coil triggers the circuit and the magnet is attracted towards the coil. Then the coil current must be switched off quickly when the magnet is centred on the coil otherwise the coil will be opposing the magnet motion as it tries to move away from the coil.

In the other case the circuit is triggered quickly just after the magnet is centred on the coil and the coil repels the magnet to propel it on its way. Later the coil current is switched off but exactly when is less important.

In the first case the switch off should be fast but in the second case the switch on should be fast.
 

Thread Starter

ranatungawk

Joined Oct 30, 2008
188
In one case the approach of the magnet towards the coil triggers the circuit and the magnet is attracted towards the coil. Then the coil current must be switched off quickly when the magnet is centred on the coil otherwise the coil will be opposing the magnet motion as it tries to move away from the coil.

In the other case the circuit is triggered quickly just after the magnet is centred on the coil and the coil repels the magnet to propel it on its way. Later the coil current is switched off but exactly when is less important.

In the first case the switch off should be fast but in the second case the switch on should be fast.
So what is the most important design for a clock ?
 
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