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Princess 4.5 inch TV

A

Andrew Tweddle

Jan 1, 1970
0
Has anyone got a schematic or a method for adapting a Princess 4.5 inch
TV to AV in. I need a small composite monitor for an old machine.

Also where could I find a composite monochrome 6 - 10 inch flatscreen
new or salvaged out of some consumer item to build into the said machine.

regards Andrew
 
M

Malissa Baldwin

Jan 1, 1970
0
Has anyone got a schematic or a method for adapting a Princess 4.5 inch
TV to AV in. I need a small composite monitor for an old machine.

Also where could I find a composite monochrome 6 - 10 inch flatscreen
new or salvaged out of some consumer item to build into the said machine.

regards Andrew

Sounds to me like somebody didn't google first.

If you do not google before posting your question I will have to send
a complant to your ISP.
 
T

Tim

Jan 1, 1970
0
Has anyone got a schematic or a method for adapting a Princess 4.5 inch
TV to AV in. I need a small composite monitor for an old machine.

Also where could I find a composite monochrome 6 - 10 inch flatscreen
new or salvaged out of some consumer item to build into the said machine.

regards Andrew
Just use an RF modulator. You can get them at Radio Shack or Walmart.

- Tim -
 
M

msg

Jan 1, 1970
0
Andrew Tweddle wrote:

Also where could I find a composite monochrome 6 - 10 inch flatscreen
new or salvaged out of some consumer item to build into the said machine.

Last year I found some interesting web sites documenting the use of
the Sony Watchman (tiny CRT-based TV with a flat screen and very slim
profile) as the embedded monitor for some clever handheld projects.

Search the web and if you can't find what you need, I'll search our
local archives.

Regards,

Michael
 
Has anyone got a schematic or a method for adapting a Princess 4.5 inch
TV to AV in. I need a small composite monitor for an old machine.


Just a case of feeding it in after the tuner, and getting a point
where the signal is the right way up. I've done this with a bigger TV.
Thankfully miniatures normally run off an ext transformer, so no psu
isolation issues.

So the challenge is finding the right point, where the signal becomes
baseband. Output of tuner is where to start. I'd either scope the
possible points first, or maybe use a piezo with series R to check
they sound right, if theres any risk to a scope.

C/R etc might be needed to tweak the input signal to suit the tv, due
to dc offset. A cap on the input is good practice, as composite
outputs can have dc on them.

I'm not sure what else you need to know.


NT
 
A

Andrew Tweddle

Jan 1, 1970
0
Just a case of feeding it in after the tuner, and getting a point
where the signal is the right way up. I've done this with a bigger TV.
Thankfully miniatures normally run off an ext transformer, so no psu
isolation issues.

So the challenge is finding the right point, where the signal becomes
baseband. Output of tuner is where to start. I'd either scope the
possible points first, or maybe use a piezo with series R to check
they sound right, if theres any risk to a scope.

C/R etc might be needed to tweak the input signal to suit the tv, due
to dc offset. A cap on the input is good practice, as composite
outputs can have dc on them.

I'm not sure what else you need to know.


NT
I eventually found a schematic of the KA7511 IC that runs the TV and it
had a generic schematic, unfortunately it was unreadable. I then
followed your advice and scoped the IC to find pin 5 was the output from
the tuner which gave me a baseband video signal. I connected up an RCA
socket to this point and I now have an external picture running over the
normal picture. Next trick is to disconnect pin5 and insert the signal
and a switch in the chain.

Thaks for the help.
Andrew
 
I eventually found a schematic of the KA7511 IC that runs the TV and it
had a generic schematic, unfortunately it was unreadable. I then
followed your advice and scoped the IC to find pin 5 was the output from
the tuner which gave me a baseband video signal. I connected up an RCA
socket to this point and I now have an external picture running over the
normal picture. Next trick is to disconnect pin5 and insert the signal
and a switch in the chain.

Thaks for the help.
Andrew

Good news. I dont know which bit of the cct sets up the dc levels
there, bit it might just be whatever you disconnect of course.


NT
 
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