Circuits & Schematics: frequency meter - 6

51. Single cell V-F converter
    Jim Williams
    Circuits Analogue Design Measurement Analog Devices LT1017
    .. from C1’s 2.2 µF summing point capacitor (Trace D) via Q5 and Q2. C1 servo-controls this oscillator to whatever frequency is required to maintain C1’s summing point near zero. Since the current into C1’s input is ...
    Jul 31, 2024

52. High stability quartz stabilized V-F converter
    Jim Williams
    Circuits Measurement Analog Devices LM199 LT1001 LT1011 LT1056 LTC1043
    .. output crosses the D input’s trip point, switching again occurs and the entire process repeats. The repetition frequency depends on the input-derived current, hence the frequency of oscillation is directly related to the ...
    Jul 30, 2024

53. Measure an optocoupler's CTR
    Chee Hua How
    Circuits Measurement Analog Devices AD620 AD734
    .. in the feedback path of a switched-mode power supply. The CTR determines the DC gain of a power supply’s open-loop frequency response, which affects the loop’s phase margin. An optocoupler influences multiple operating ...
    Jul 25, 2024
54. Single supply 200kHz VFC with bipolar differential inputs
    Stephen Woodward
    Circuits Analogue Design Measurement Microchip LM4040
    .. methods for analog to digital conversion are more “mature” than the classic combination of a voltage-to-frequency converter (VFC) with a counter. VFC digitization is naturally integrating, so good noise rejection is ...
    Jul 24, 2024
55. Low-power ambient light sensing LED driver, with hibernate mode
    Chau Tran
    Circuits Supply Light Analog Devices ADA4807-1
    .. asymptotically approaches the comparator output voltage with a time constant RC. This time constant RC determines the frequency of the oscillation. The duty cycle of the signal can be adjusted by changing the ratio of resistance of ...
    Jul 22, 2024
56. Voltage inverter design idea transmogrifies into a 1MHz VFC
    Stephen Woodward
    Circuits Analogue Design Measurement NXP 74HC4053
    .. capacitor C2 is reduced by several orders of magnitude. This makes the current pumped directly proportional to oscillator frequency: Starting from that idea, then adding some simple discrete components, our original inverter circuit ...
    Jul 18, 2024
57. A low power, low cost, differential input to a single-ended output amplifier
    Chau Tran Jordyn Rombola
    Circuits Analogue Design Amplifiers Analog Devices ADA4807-2
    .. voltage is typically larger than the differential input voltage. The effectiveness of the rejection diminishes as the frequency of the common-mode voltage increases. Amplifiers within the same package have better matching, the same ...
    Jul 15, 2024
58. Low-power, low-cost, differential amplifier with high CMRR
    Chau Tran Jordyn Rombola
    Circuits Amplifiers Analog Devices ADA4805-2
    .. IN+ and IN pins. In this case, the gain resistors become part of the input resistance for the source. The differential-mode frequency response plot was taken by applying a differential input voltage at the two input terminals (IN+ and IN ...
    Jul 10, 2024
59. Difference amplifier measures high voltages
    Chau Tran Moshe Gerstenhaber
    Circuits Analogue Design Measurement Analog Devices AD629BR
    .. to the feedback gain to stabilize the circuit and maximize the system bandwidth. The following equation calculates the pole frequency, f P : The following equation determines the zero frequency, f Z : Figure 3. The circuit in Figure 2 ...
    Jul 1, 2024
60. Portable thermal anemometer hot-transistor bias compensation nulls battery discharge droop
    Stephen Woodward
    Circuits Measurement Texas Instruments LM393
    .. Darlington pair” ( Ref. 2 ) and in Figure 1. Figure 1. Constant-temperature anemometer with direct power-to-frequency conversion. Figure 1’s anemometer is unusual because it melds the sensor transistor into a direct ...
    Jun 27, 2024

Sort by: relevance / date