GB1243406A - Improvements in electronic circuits - Google Patents

Abstract

1,243,406. Control system. INSTRON Ltd. 8 July, 1969 [26 July, 1968], No. 35841/68. Heading G4H. [Also in Division H3] An electronic control system comprises a number of logic modules A, B &c., each having a signal input I/P, at least one reset input connected to a reset line RL, and a load output 0/P and each consisting of a number of NOR gates T, the modules being connected in parallel to the lines RL and SL so that a reset signal is applied through the lines in response to actuation of an input to any module to reset any previously switched on module, the module having the energized input being inhibited from producing any output signal until completion of the resetting. Two embodiments are described. In the illustrated embodiment a threshold amplifier A, is arranged to trigger when signals indicating that more than one module is switched on are received at its input from summing line SL, the output of the amplifier resetting all the modules via line RL. However due to the persistence of the manual input to the second previously switched on module after the resetting operation this second module is switched on again. In a further embodiment, Fig. 3 (not shown), each module is connected to each of the lines RL and SL by a pair of NOR gates in series and one of the NOR gates making up the module is arranged to gate the manual input signal to the module. When a second module is "switched on" a reset signal is applied to line RL and the second module is prevented from switching on by the gating NOR gate until the previously switched on module has been reset. When the previously switched on module resets the input gate in the second module is cleared and the second module switches on. The Specification states that the output from each of the modules may control an electromagnetically actuated clutch, and that further modules, e.g. D, may be added as required. Furthermore the sensitivity of the threshold amplifier in the first embodiment may be adjusted so as to trigger when n or more modules are energized, thereby allowing n-1 modules to produce on output simultaneously.