Foster–Seeley discriminator The Foster–Seeley discriminator is a common type of FM detector circuit, invented in by Dudley E. Foster and Stuart. FOSTER-SEELEY DISCRIMINATOR The FOSTER-SEELEY DISCRIMINATOR is also known as the PHASE-SHIFT DISCRIMINATOR. It uses a double-tuned rf. Foster Seeley Discriminator – Download as PDF File .pdf), Text File .txt) or read online. foster.
|Published (Last):||2 August 2008|
|PDF File Size:||2.82 Mb|
|ePub File Size:||16.86 Mb|
|Price:||Free* [*Free Regsitration Required]|
C5 is the output coupling capacitor. He agreed to temporarily occupy one of the teaching pos Communication circuits Revolvy Brain revolvybrain.
Demodulation is extracting the original information-bearing signal from a carrier wave. Also, because L3 is effectively in parallel with the primary tank circuit, input voltage Ep also appears across L3. The same vector diagrams apply to the ratio detector but will not be discussed here.
Member feedback about Stuart William Seeley: After graduating in from the University of Delaware, he earned a J.
The voltage drop across R4 is larger than that across R3 and the discrimiator across both is negative. Notice that secondary voltages e 1 and e2 are still degrees out of phase with the current iS that produces them.
Foster Seeley Discriminator | FM Radio Detector Demodulator | Tutorial
From he was an amateur radio experimenter and commercial operator, then worked at General ElectricSparks Withingtonand the RCA License Laboratory, starting in The output is taken between points A and B. They are key components in many electronic devices, particularly radio equipment, used in circuits such as disciminator, filters, tuners and frequency mixers. The waveforms for the circuit are shown in figure Member discriminnator about Chris Christie: As the frequency of the input changes, the balance between the two halves of the transformer secondary changes, and the result is a voltage proportional to the frequency deviation of the carrier.
The current flowing in the tank causes voltage drops across each half of the balanced secondary winding of transformer T1. Because of this heavier conduction, the voltage developed across R3 is greater than the voltage developed across R4; the output voltage is positive.
There is a small intake at 10 into Old Gramma Foster—Seeley discriminators are sensitive to both frequency and amplitude variations, unlike some detectors. The secondary winding of T1 L2 and capacitor C2 also form a tank circuit tuned to the center frequency.
As a result of its advantages and disadvantages the Foster Seeley detector or discriminator is not widely used these days. Both the ratio detector and Fostef detectors are expensive to manufacture.
Offers good level of performance and reasonable linearity. The secondary current i lags the primary voltage ep. The two grid signals move more in phase, as shown in view Iand the average plate current increases, as shown in view J. R1 and R2 are not always necessary but are usually used when the back reverse bias resistance of the two diodes is different.
Foster–Seeley discriminator – Wikipedia
Fosterr electrical engineers Revolvy Brain revolvybrain. Narrower bandwidth than the ratio detector. The vector sum of Ep and e2 is larger than that of e and e1. Engineering in your pocket Download our mobile app and study on-the-go. When closed, the gate completely stops the beam. Any wound components like the RF transformers are expensive to manufacture when compared with integrated circuits produced in vast numbers.
The quadrature grid acts much the same as the limiter discrimiinator it either opens or closes the passage for electrons.
Note in view H that the two grid signals have moved more out of phase and the average plate current level sefley decreased. The circuit topology looks very similar, having a transformer and a pair of diodes, but there is no third winding and instead a choke is used.
A transformer, tuned to the carrier frequency, is connected to two rectifier diodes. Lawrence University alumni Revolvy Brain revolvybrain. All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.