Frequency to Voltage Converter Using LM2907
Category: Miscellaneous
Designer: RANA MUHAMMAD ADNAN KHALIL
Notes
This circuit is designed and simulated in proteus 7.10. This is very useful circuit for converting frequency into voltage using LM2907. 1. Very few components needed for frequency to voltage (f to v) conversion. 2. Just two capacitors (10nF and 1uF) and two resistors (100k and 10k) needed for this f to v circuit. 3. The input frequency is given at pin 1 of LM2907 and output is taken from pin 4 and 7 (both shorted) accross resistor R2. 4. The input supply is +15VDC. 5. By using C1 10nF, the conversion ratio is Vout = 67Hz per volt Vout = Fin x Vcc x R1 x C1 = 1.005V per 67Hz 6. You can see this conversion in animation, we applied 70Hz and 140Hz and output voltage is around 1V and 2V respectively. 7. You can increase the conversion ratio by increasing capacitor C1 and similarly decrease conversion ratio by decreasing C1. Applications: 1. This circuit can be used as a tachometer. 2. It can also be used to measure both rpm and frequency. Note: More circuits are coming soon.