Improvements relating to apparatus for testing electrical control systems

摘要

704,883. Test apparatus for automatic control systems. EVERSHED & VIGNOLES, Ltd. March 26. 1952 [April 3, 1951], No. 7734/51. Class 38 (4) Apparatus simulating the liquid level signals from a continuously fed tank is provided for testing an automatic control system which maintains the level constant by adjusting the outlet, especially a system as described in Specification 704,885. A capacitor 150 representing the storage tank is charged from a photo-electric galvanometer unit of the type used in the control system, and having one coil 170 fed at terminals f, g with the output current of the control system (which would normally be connected to the outlet valve servomotor) and the other coil 171 fed with a constant but adjustable current representing the input to the tank. The capacitor 150 is connected in the grid circuit of a valve 151 having one winding 155 of a moving coil relay in its anode circuit to provide liquid level signals at terminals c, d, e, for the first valve of said control system. The other coil 156 is connected at terminals a, b in the feed-back circuit from said first valve, i.e. this relay replaces the liquid level detecting relay in the control system. The constant current circuit comprises a valve 190 having the operating coil 193 of a relay in its cathode circuit to vary the charge on a capacitor 206 generally as described in Specification 688,464.