The LM2907 and LM2917 devices are monolithic frequency-to-voltage converters with a high-gain op amp designed to drive a relay, lamp, or other load when the input frequency reaches or exceeds a selected ratio.
The op amp is fully compatible with the tachometer and has a floating transistor as its output. This feature allows ground or supply source load up to 50 mA. The collector can be taken above VCC up to a maximum of 28 V VCE.
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