Before 1682filter test box, a two winding leads on rear end of the internal circuit connection, be measured filter lead crossover defective products, the skeleton of the filter, the operator can judge the eyes bad products, but to no skeleton of the toroidal core filter, operator not distinguishing the bad products. Therefore decided to increase the discriminant filter lead crossover defect discriminant function, double coil filter design for winding leads on one side, if the two set lead crossover, filter side winding is not, such as side winding is electrified, lead without crossover filter.

Circuit2051 and the host through the 232communication, filter test circuit halts the unlikely, but the host is unable to discriminate filter test circuit is dead, so keep the reset circuit, JP1 is reset input. The host through the 232orifice priming filter test circuit, can be used flexibly and as it used to. Filter test chip retention start circuit, filter test box singlechip start circuit is illustrated as follows:74LS74D flip-flop reset connected to the positive terminal, a89C2051P3.7," D" ground zero, starting chip CLK through JP2keys connected to the positive, i.e. to give CLK a rising edge trigger pulse, type D Q end by high falls to zero, the trigger 2051" external interrupt0",2051in response to interrupts, interrupt program into the measurement procedures. 2051 in response to an interrupt will D flip-flop is set to" high", i.e. a start.