Miniature television transmitter
First Claim
1. A tv transmitter comprising:
- a video amplifier for amplifying a composite video signal applied at an input thereof;
a single ended differential amplifier connected to said video amplifier for amplifying the output of said video amplifier;
a low pass filter connected to the output of said differential amplifier for filtering out high frequency components;
a modulator connected to receive the output of said low pass filter and an r.f. carrier for modulating the video signal output from said low pass filter onto said r.f. carrier; and
bias circuit means connected to said video amplifier for providing a variable bias thereto to adjust the dc level of said video signal.
2 Assignments
0 Petitions
Accused Products
Abstract
A small lightweight portable television transmitter having few components and operable with NTSC, PAL and SECAM systems. A one transistor video amplifier receives a gain controlled video signal and adjusts the d.c. level. Common mode noise rejection and sync pulse stretching is provided by a two transistor single ended output differential amplifier. The r.f. modulator combines and emitter follower and a one transistor mixer, with the r.f. applied to the collector and the modulating signals, including video and an audio modulated subcarrier, applied to the base. The transmitter has less than about 210 electrical components, weighs less than 1 kg when constructed with discrete components and substantially less when integrated into a hybrid circuit, yet provides 3 watts minimum peak power.
-
Citations
41 Claims
-
1. A tv transmitter comprising:
-
a video amplifier for amplifying a composite video signal applied at an input thereof; a single ended differential amplifier connected to said video amplifier for amplifying the output of said video amplifier; a low pass filter connected to the output of said differential amplifier for filtering out high frequency components; a modulator connected to receive the output of said low pass filter and an r.f. carrier for modulating the video signal output from said low pass filter onto said r.f. carrier; and bias circuit means connected to said video amplifier for providing a variable bias thereto to adjust the dc level of said video signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 39, 40, 41)
-
-
26. A tv transmitter as claimed in claim 45 wherein said r.f. sniffer is connected to the output of said tunable linear amplifier.
-
27. A tv transmitter comprising:
-
a video amplifier for amplifying a composite video signal applied at an input thereof; a single ended differential amplifier connected to said video amplifier for amplifying the output of said video amplifier; a low pass filter connected to the output of said differential amplifier for filtering out high frequency components; and a modulator connected to receive the output of said low pass filter and an r.f. carrier for modulating the video signal output from said low pass filter onto said r.f. carrier; and bias circuit means connected to said differential amplifier for applying a variable bias thereto to adjust the width of the sync pulses in the composite video signal applied thereto from said video amplifier. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
-
Specification