It combines a number of features with a clever circuit to allow a single 1,000u to be charged to 35v and produce sufficient energy to operate a point. It also has an on-board mini toggle switch and two indicator LEDs - this reduces your wiring. The first electrolytic on the PC board is called a RESERVOIR CAPACITOR as it does not play any part in the delivery of the energy to the point, but it sits between the positive and 0v rail to reduce the impedance of these two rails. When the toggle switch is in the UP position, the other electrolytic gets charged and it puts a heavy load on the supply when this is happening. This is when the peak current is drawn at the beginning of the charging cycle and rather than taking a lot of current from the supply, it draws much of the energy from the RESERVOIR CAPACITOR - about 80% to 90%. This energy is taken from the Reservoir Capacitor during the initial part of the cycle and the power supply assists during this time as well as the remainder of the time when the DELIVERY CAPACITOR is charging to its final value. This results in a very short charge-time. When the switch is in the DOWN position, all the energy in the DELIVERY ELECTROLYTIC is passed to the point and the rest of the circuit is not involved. Normally, the DELIVERY ELECTROLYTICS take a period of time to recharge, but with this circuit the Reservoir capacitor contains a lot of the recharge energy and the supply only has to supply a small additional amount during the activation and the remaining amount can be delivered after the point has changed position. This means the point can be changed from one position to the other repeatedly, in less than a second. The circuit also includes a voltage doubling arrangement for 12vAC to 15v AC - (from a train power supply) and two indicator LEDs to show the position of the point. The mini toggle switch can be easily fitted to your console and small holes on each side of the switch used for the LEDs to shine through the console. All these features are in this narrow PC board so that a row of these modules can be aligned on a panel to show the position of the points. This module reduces your wiring considerably as only 3 wires are needed for each point and a common "bus" of positive and negative to the modules. THE CIRCUIT
The circuit looks simple but the action of
the toggle switch produces two different paths for the DELIVERY
ELECTROLYTIC and the two power diodes connected to the ends of the
solenoid determine which coil will be activated. These 3 photos below clearly show how
the components are fitted and especially the switch. It is soldered with
the middle tag to the top of the board and one of the wires cut from the
1,000u electro is pushed into the hole next to the switch and bent over.
It is soldered to the top tag. The same is done under the board.
All the components fit on the PC
board and the module comes with 2 x 1,000u electrolytics. The input can
be 12vAC to 15vAC or 20vDC to 35vDC.
This module requires a
supply of 35-36v to get the maximum output.
CONSTRUCTION
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