Multimeter Capacitance Function
When an electrician uses a digital multimeter, according to the function of the capacitance in the circuit, the basic function of the capacitor is charging and discharging, but many circuit phenomena extended from this basic charging and discharging function make the capacitor have various uses, such as in electric motors In electronic circuits, electricians use it to produce phase shifts; in photographic flashlights, use it to generate high-energy instantaneous discharges, etc.; and in electronic circuits, capacitors of different properties are used in many different ways. The difference, but because of its function all comes from charging and discharging. Here's what some capacitors do:
Coupling capacitor function: The capacitor used in the coupling circuit is called a coupling capacitor. This kind of capacitor circuit is widely used in the resistance-capacitance coupling amplifier and other capacitive coupling circuits to block DC and AC.
Filter capacitor function: The capacitor used in the filter circuit is called a filter capacitor. This capacitor circuit is used in power filtering and various filter circuits. The filter capacitor removes signals in a certain frequency band from the total signal.
The function of the decoupling capacitor. The capacitor used in the decoupling circuit is called the decoupling capacitor. This capacitor circuit is used in the DC voltage supply circuit of the multi-stage amplifier. The decoupling capacitor eliminates the harmful low-frequency cross-connection between the amplifiers of each stage. .
The function of the high-frequency vibration elimination capacitor: the capacitor used in the high-frequency vibration elimination circuit is called a high-frequency vibration elimination capacitor. In the audio negative feedback amplifier, in order to eliminate the high-frequency self-excitation that may occur, this capacitor circuit is used. In order to eliminate the possible high frequency howling of the amplifier.
Resonant capacitor function: The capacitor used in the LC resonant circuit is called a resonant capacitor, which is required in both LC parallel and series resonant circuits.
Bypass capacitor function: The capacitor used in the bypass circuit is called a bypass capacitor. If you need to remove a certain frequency band signal from the signal in the circuit, you can use a bypass capacitor circuit. According to the frequency of the signal to be removed, there are all Frequency domain (all AC signals) bypass capacitor circuits and high frequency bypass capacitor circuits.
Function of neutralization capacitor: The capacitor used in the neutralization circuit is called neutralization capacitor. In radio high-frequency and intermediate frequency amplifiers, and TV high-frequency amplifiers, this neutralization capacitor circuit is used to eliminate self-excitation.
Timing capacitor function: The capacitor used in the timing circuit is called a timing capacitor. A timing capacitor circuit is used in a circuit that requires time control through capacitor charging and discharging, and the capacitor plays a role in controlling the time constant.
Integral capacitance function: The capacitor used in the integral circuit is called integral capacitance. In the synchronous separation circuit for electric potential field scanning, the field synchronous signal can be taken out from the field compound synchronous signal by adopting this integral capacitance circuit.
Differential capacitance function: The capacitor used in the differential circuit is called differential capacitance. In order to obtain the peak trigger signal in the trigger circuit, this differential capacitance circuit is used to obtain the peak pulse trigger signal from various (mainly rectangular pulse) signals.
Compensation capacitor function: The capacitor used in the compensation circuit is called compensation capacitor. In the bass compensation circuit of the deck, this low-frequency compensation capacitor circuit is used to enhance the low-frequency signal in the playback signal. In addition, there are high-frequency compensation capacitor circuit.
The function of the bootstrap capacitor: The capacitor used in the bootstrap circuit is called a bootstrap capacitor. The commonly used OTL power amplifier output stage circuit uses this bootstrap capacitor circuit to slightly increase the positive half-cycle amplitude of the signal through positive feedback.
The function of the frequency division capacitor: the capacitor in the frequency division circuit is called the frequency division capacitor. In the speaker frequency division circuit of the speaker, the frequency division capacitor circuit is used to make the high frequency speaker work in the high frequency band, and the intermediate frequency speaker work in the mid frequency band. , the subwoofer works in the low frequency band.
The function of load capacitance: it refers to the effective external capacitance that determines the load resonance frequency together with the quartz crystal resonator. Commonly used standard values for load capacitance are 16pF, 20pF, 30pF, 50pF, and 100pF. The load capacitance can be adjusted appropriately according to the specific situation. Generally, the operating frequency of the resonator can be adjusted to the nominal value through adjustment. There are many other capacitive functions in digital multimeters, mainly to see what objects most need to be measured when electricians use digital multimeters.
