Advantages of full rectification: Permits a large (significant) increase in the tube rating or heat loading capacity (output capacity); results in larger exposures that can be used w/out damaging the tube; higher ma and kvp settings
An advantage of a full-wave rectification is that it permits a significant increase in the Power Output Capability of radiographic equipment which results in larger exposures.
Determing rectifier failure? When one rectifier fails in a single phase full wave (four) rectifiers, it operates as a two diode (half wave) rectifier;produces a drop in the millimeter reading to about one half the normal value; this causes radiographic underexposure.
Diode rectification(during reverse bias)? When the positive terminal of the AC source is connected to the N-end and the negative terminal to the P-end, electrons and holes move away from each other increasing the barrier voltage and preventing current across the junction.
Diode rectification: (during forward bias)? When the negative terminal of the AC source is connected to the N-end and the positive terminal to the P-end, electrons flow toward each other reducing the barrier voltage allowing current to flow across junction and external circuit.
Diode Rectification? A type of rectification that uses solid state diode rectifiers. It is made of semiconductors.
Diode rectification? Uses solid-state diode rectifiers; made of semiconductors of which silicon is the most commonly used.
Diode? It is an electronic device that contains two electrodes.
Disadvantage of self-rectification? Low heat loading capacity of an x-ray tube; danger of overheating the anode, causing thermionic emission;can destroy filament
Disagvantages of full rectification? Using the entire AC wave results in the production of a high percentage of low energy x-rays, or low kv range
During a rectifier failure, when one rectifier fails in a single phase full wave rectified system, it operates as a two-diode rectifier. It produces a drop in the milliammeter reading to about one-half the normal value which then causes Radiographic Underexposure.
Forward Bias? The process when the negative terminal of the AC source is connected to the N-end and the positive terminal to the P-end, electrons and holes flow toward each other, reducing the barrier voltage, allowing current to flow across the junction and the external circuit.
Full wave rectification is also called what? Two pulse recitfication since there are two voltage peaks per cycle; four rectifier diodes are connected; 120 pulses per 60HZ
Full wave Rectification? Changing the negative half to a positive; converts opposing half of AC cycle so current (electrons) is always moving in the same direction.
Full wave rectifiers consist of? Four diode “bridge” configuration with single phase.
Full-Wave Rectification? This is the type of rectification that converts the opposing half of the AC cycle so that electrons are routed toward the cathode. This is also called “two-pulse” rectification since there are two voltage peaks per cycle. It is accomplished through an ingenious arrangement of four rectifiers in a bridge circuit. If a single rectifier fails in a full-wave unit, it will act as a half-wave unit going from 120 pulses to 60 pulses per second. 120 pulses per 60Hz current.
Half wave rectification is also called what? One-Pulse Rectification; it has one voltage peak per cycle; accomplished in self rectification; can use one or two diodes to work; 60 pulses per 60 Hz
Half wave rectification? Suppresses the opposing half of the incoming AC cycle. (Represented by the half of the curve that lies below the line.)
Half wave Rectifier Circuit? X-ray tube connected to secondary of high voltage transformer through diode rectifiers. Has alternating voltage applied to secondary of high voltage transformer.
Half-Wave Rectification? This is the type of rectification that suppresses the opposing half of the incoming AC cycle, specifically the negative half cycle. It is also called the “one-pulse” rectification. The opposing half of the flow is ignored and not utilized. It can be accomplished by using one or two diodes. 60 pulses per 60Hz current.
Negative Half cycle? The opposing half of the flow is ignored and not utilized
N-type Semiconductors? These have loosely bound electrons that are relatively free to move about inside the material.
P-N Junction? This is formed when the n-type and p-type material are combined in where electrons are allowed to flow only in one direction.
P-type Semiconductors? These have electrons traps, spaces where electrons can be found. These positive traps, called holes, can also be viewed as being free to migrate through the material.
Rectification? It is the process by which alternating current is changed to pulsating direct current. It also permits electrons to flow easily in one direction while offering high resistance to movement in the other direction.
Rectifier function? Permits electrons to flow easily in one direction while offering high resistance to movement in the other direction.
Reverse Bias? The process when the positive terminal of the AC source is connected to the N-end and the negative terminal to the P-end, electrons and holes move away from each other, increasing the barrier voltage and preventing current across the junction.
Self tube rectified circuit? Xray tube acts as a rectifier current only flows from cathode to anode; cathode is source of free electrons
Semiconductors are classed in two types? N type and p type
Semiconductors are classified into what two types? N-type and P-type
Silicon? It is the most commonly used semiconductor.
The x-ray tube serves as a Diode? The xray tube allows passage of electrons only from the cathode to the anode during the positive half-cycle of the AC curve.
The x-ray tubes operates best when receiving direct current meaning it’s coming from the Cathode to the Anode.
This has 120 pulses per 60Hz current? Full wave rectification
This has 60 pulses per 60Hz current? Half wave rectification
What determines rectifier failure in a single phase system? When one rectifier fails in a single phase full wave (four rectifier) it operates as a two diode half wave rectifier which produces a drop in reading to half one half the normal value.
What happens when a single rectifier fails in a full wave circuit? It will act as a half wave unit going from 120 pulses to 60 pulses per second.
What is the advantage of full rectification in relation to a radiograph machine? Rectification permits a large increase in the tube rating or heat-loading capacity.
What is the principle disadvantage of self-rectification in relation to a radiograph machine? The principle disadvantage of self-rectification is the low heat loading capacity of an xray tube in a circuit and exposure factors are limited to lower values.
X-ray tubes operate best when recieving? Direct current from the cath