Archive for the ‘Basic Function Circuits’ Category
Shunt Series Pair Wideband Amplifier
This is a Shunt Series Pair Wideband Amplifier circuit. This circuit has four feedback loops, they are two emitters feedback, shunt-shunt feedback and an AC feedback loop(series-shunt). This is a very stable circuit and can be used for wideband amplifiers and low gain. This circuit requires +12 supply that restrict the “headroom” of the second …[Read More]
Single Transistor Blocking Monostable
Below is a schematic diagram of blocking monostable circuit. The normal state of the transistor is off because the 10 k resistor has been removed. The conduction will be started using a positive pulse at node “a” and the transformer will do the rest. The transistor will again be turned off (by a hefty …
Circuit below is circuit of a transistor blocking oscillator. The transformer is phased. This cause any increase in collector current pulls the base up, further increasing the current. The transformer may the the most appropriate but not the most optimum. Any fluctuation in the collector current is fed back and reinforced because the 10k resistor …[Read More]
UJT Relaxation Oscillator with Op-Amp Squarer
The UJT below is configured to produce a sawtooth wave at a frequency of 104 Hz. The capacitor begins to charge through the 4.7 kOhm resistor when the circuit is initially powered up. The current suddenly flows from the UJT emitter (E) to the UJT Base (B1) when the voltage across the capacitor rises to …[Read More]
TRIAC Basic Operation
Triode for alternating current,TRIAC, is an electronic component that can control power in two direction in an AC circuit. The figure (a) shows the block construction and schematic symbol of TRIAC. The TRIAC is operated like two SCRs in parallel connection in opposite direction like shown in figure (b). Here is the figure of TRIAC: …[Read More]
SIDAC Basic Operation
Silicon Diode for Alternating Current, SIDAC, is a multilayer silicon semiconductor switch. This component is triggered by voltage and can be operated as bidirectional swtch. Usually, this SIDAC is used in cheap high voltage power supply or ignition circuits. Figure below shows SIDAC block construction, schematic symbol and geometric construction : The SIDAC has leakage …[Read More]
DIAC Basic Operation
Diode for alternating current is a trigger diode which conducts current only after the DIAC reach the breakdown voltage. The breakdown voltage of DIAC is 30 V. It has construction like an open base NPN transistor. The DIAC can be used in many application such as motor speed controls and light dimmers circuit. Figure below …[Read More]
| 
