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close this bookRadio and Electronics (DED Philippinen, 66 p.)
close this folder10. BLOCKS OF RADIOS / -1- / POWER SUPPLIES
View the document10.1. GENERAL CONSIDERATIONS
View the document10.2. TRANSFORMER
View the document10.3. THE RECTIFIERS.
Open this folder and view contents10.4. SMOOTHING AND FILTER CIRCUITS
Open this folder and view contents10.5. STABILIZATION

10.1. GENERAL CONSIDERATIONS

Kind of supply voltage:

Radio receivers like most of the electronic nowadays need for good performance a -dc-voltage which is very stabil.

Reason:

Every change of the supply voltage acts on the receiver like an injected signal and this means distortion.

Energy source:

Nowadays mostly batteries or powersupplies from mains.

Amount of supply voltage:

Depending on the kind of “active-components” used in the receiver. For valve receivers “high tension” (75 - 350 V), for transistor receivers (3 - 24 V).

Stages in a power supply:

According to the problems arising in a special case, there are different stages necessary in a power-supply in order to have the constant dc-voltage required.

Energy source

stages required

kind of radio supplied

mains

---------

transforming

rectifying

smoothing

stabilizing

working

batteries

chopping

transforming

rectifying

smoothing

stabilizing

with valves

batteries

---------

---------

---------

---------

stabilizing

working with

Mains

---------

transforming

rectifying

smoothing

stabilizing

transistors

Chopping is not a topic of this course, therefore the most complicated with here is the supply of a transistorracio by the mains which is shown in blocks in fig. 87.


figure