Analogue simulator for mine ventilation - uses standard rack into which modules e.g. for control and ventilation can be installed to suit desired configuration

摘要

The regulator contains a calculation circuit which matches the voltage to an output current to represent pressure in millimetres of water. A sampling circuit generates a voltage drop proportional to the current for application to an amplifier (1). The amplifier output is inverted (2) for a summer (3) with coefficients (A,B) from a parabolic curve. The summer and inverter outputs are multiplied (4) and an output summer (5) enables a second order differential equation to be solved. A comparator (6) produces an error signal which is amplified by the open loop gain to control operation of a test circuit (7). A second comparator (8) analyses the signal with a reference voltage to provide an output for an opto-coupler (9) to control the output summer (5). This prevents the second mathematical solution from being obtained.