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test instruments projects
BH4534B
BH4534B frequency counter schematics Low cost 9 ½-digits frequency counter

The previous BH4534A low cost frequency counter has been improved with two fast decade counters preceded the HEF4534B circuit and with two slow decade counters connected to terminal count output of HEF4534B. Additionally a Flip-Flop has been added to terminate the counter decade. The display has been changed to LED numeric display with integrated latch and decoder. Frequency standard is 10 MHz oscillator with decade dividers to 1 sec gate signal.

The counter has 9½ digits and maximum frequency range of 135 MHz. The counter measures also a period or time between two events with a selectable resolution of 1 sec or 1msec or 1usec or 100 nsec.

The power consumption is about 650 mA at 5V DC.