What is the purpose of clamping diode in a positive diode AND gate?

Why the n-jfet is operated with the negative voltage not the positive voltage?

In a JFET the only insulation between the gate and the channel is a reverse biased diode junction, if this junction becomes forward biased then the gate and channel are effectively shorted and the device no longer acts as a transistor (it will act as a forward biased diode instead). In the n-channel JFET, the gate is the P-side of this diode and the channel is the N-side of this diode. To keep this diode reverse biased (and the device operating as a transistor) therefor the gate MUST always be maintained at a voltage more negative than the most negative section of the channel.

Why diode logic gate is not suitable for cascading operation?

the pullup or pull down resistance in the diode logic gate makes it a high output resistance device.If u try to drive another diode logic gate with it the output voltage of the first gate will be affected by the resistance in the second gate.A diode logic gate should always drive a high input resistance input.

Difference between optocoupler and normal diode?

Purpose: An optocoupler (or optical isolator) uses optics to isolate one circuit from another. The diode in the optical isolator is similar to an LED. The light from this LED controls the gate or base of a transistor. A diode has two terminals, an optocouple will have at least 4. A diode is used to control current flow direction; an optocoupler main purpose is to isolate one circuit from another. etc. etc.

When does the diode not allowed to flow the current?

A diode is a one-way gate for electrical current to flow through. You must have the right size diode for the amount of current that will be used in your circuit. The stripe on the diode is your output end. That is, the current must enter your diode at the non-stripe end and leave at the end with the stripe. This coincides with the diode symbol used on your schematic. If your diode is in backwards, the circuit will not work as the gate in the diode will block the current just the way it should.

Can an OR gate have one input?

Technically, an OR gate could function with only one input, in which case it would perform the same as if it was not present; when its only input goes high, it would go high, and when the input goes low, it would go low. As a practical matter, the only useful purpose of a single input OR gate would be to have it act as a simple diode, which would be more efficient to simply have a diode in its place.

How do you use a thyristor as a diode?

A thyristor, also known as a silicon controlled rectifier, is a diode that can be turned on by application of a small gate voltage.

What is the difference between a Shockley diode and a Shottky diode?

A Shockley diode is a primitive diode identical to a thyristor with it's gate left disconnected. A Schottky diode is similar to a normal avalanche diode except that it's forward voltage is quite low, and it's switching speed is very high.

Difference between silicon-controlled rectifier and diode?

silicon controlled rectifier is a 3 terminal 4 layer device which has 2 consecutive P N junctions here the three terminals called anode, cathode and gate gate controls the conduction of the scr but diode just conducts in forward bias and blocks in reverse bias

Why not use and symbol in string function?

You shouldn't use it because it is not and gate in diode logic.

What is the difference between a diode and scr?

A diode mainly consists of only 2 terminals(anode,cathode).A SCR mainly contains one more terminal called GATE.The main purpose of the gate in an SCR is just to provide pulses.The main draw back of SCR is it is not fully controllable device.

How do you measure IGBT?

Digital multi-meter (DMM) test procedure:Equipment Requirement - DMM with diode check mode and battery voltage less than 20V. (Typical units using 9V battery are OK).Collector-Emitter Junction test: With the module out of circuit remove the conductive foam and short the gate to emitter.With DMM in diode check mode, the collector to emitter should give a normal diode reading with positive on the emitter and negative on the collector.The DMM should read open or infinite with positive on the collector and negative on the emitter. Damaged IGBTs may test as shorted in both positive and negative directions, open in both directions, or resistive in both directions.Gate Oxide test: With the DMM in resistance mode the resistance from gate to collector and gate to emitter should read infinite on a good device. A damaged device may be shorted or have resistive leakage from gate to collector and/or emitter.

Why is a diode used?

Broadly, diodes can be used for rectification, clamping, voltage drop, and gating. As a rectifier, the diode is used to convert an AC voltage (often from a transformer) to a DC voltage. In the simplest design, the half-wave rectifier, the diode is connected between the AC voltage and the DC voltage, and capacitors are connected across the DC voltage output. The AC voltage is a sine wave that goes both positive and negative. At the brief times that the AC voltage is higher than the DC output voltage, the diode conducts, like a closed switch, and transfers energy to the capacitor(s). At other times, the diode is reverse-biased (its anode voltage is lower than its cathode voltage) and it behaves like an open switch. The capacitor(s) act as a reservoir to provide a (relatively) steady DC voltage. Rectification is used in switching power supplies. A high-frequency AC voltage is fed into a compact transformer, which provides the electrical isolation required in the power supply, and the transformer's output is rectified as described above, except that the frequency of the AC voltage is typically 50,000 to 100,000 Hz, rather than 60 Hz. This requires high-speed, high-current diodes. In clamping, the diode is connected so that it will conduct (i.e. its anode will be more positive than its cathode) at times when energy needs to be dissipated, as is often required with inductive loads. When the current flow to the inductor is interrupted, the inductor can generate very large voltage spikes (back EMF), which should be clamped. Usually the diode dumps energy from these spikes into a "soft" load made from resistors and capacitors. Most of the energy is dissipated in the resistors in the soft load. A diode can be used to provide a relatively steady voltage drop of between 0.6 and 1.2 volts (depending on the diode type and the current) when a steady current is passed through it. The anode is more positive than the cathode. This can be useful in the design of various types of electronic circuits. The voltage drop is temperature-dependent - higher temperature causes lower voltage drop, so this can be used for temperature compensation of another part of a circuit. The simplest example of gating using diodes is the diode "OR" gate. Two diodes are connected with their cathodes together; this is the output of the gate. The two anodes are inputs to the gate. When positive DC voltage is present at either input, the respective diode will conduct and feed that voltage through to the output. This can be used to "gate" multiple supply sources (e.g. an adapter supply and a backup battery) together, or at lower currents in control circuitry.