This LM139, 239, or 339 comparator configuration appears elsewhere in this site and this section. The supply voltage may typically be between 5 and 12 V and the active cycle of the output signal depends on the relationship between R1 and R2.
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This LM139, 239, or 339 comparator configuration appears elsewhere in this site and this section. The supply voltage may typically be between 5 and 12 V and the active cycle of the output signal depends on the relationship between R1 and R2.