The two Joslyn™ circuit boards shown above are used by Joslyn in both their zero-voltage control for capacitor banks and also their Point-of-Wave™ controls for arc furnaces. Shown opposite the Joslyn boards are the Vacuum Electric Switch foot-print and plug-for-plug compatible replacement boards. The SCR boards are functionally equivalent except that the VES board part no. 1002100G1 has transient suppression components on the board whereas the Joslyn board requires that they be installed at the terminal connections during the board installation.
The timing boards while functionally equivalent are designed using different concepts. The Joslyn timing board has analog circuitry to control the timing. The timing adjustments are made by turning three trip potentiometers on the board. The Vacuum Electric Switch timing board has digital circuitry. The timing is controlled with crystal oscillator, and the switch timing can be digitally set in increments of 25 microseconds. The VES digital board has an RS232 connection which can be connected to a computer used to measure and set switch timing.
|VES Timing Boards|
|Voltage||VES part No.|