Microvitec Monitor 1451MS4
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1976/77 Rank Arena AC6333 – Worlds First Teletext Receiver
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1983 Sanyo Brochure
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Want to tell us a story?
Video Circuits V15 – Tripler Tester
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Remove Teletext Lines & VCR Problems
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Website Refresh
Colour TV Brochures
1970s Lounge Recreation
CrustyTV Vintage Television Museum
Linda Lovelace Experience
Humbars on a Sony KV2702
1972 Ultra 6713
D|E|R Service “The Best”
The one that got away
Technical information
Microvitec Monitor 1451MS4
BBC Microcomputer TELETEXT Project
Viewdata, Prestel, Philips
Philips Model Identification
1976/77 Rank Arena AC6333 – Worlds First Teletext Receiver
PYE 1980s Brochure
Ceefax (Teletext) Turns 50
Philips 1980s KT3 – K30 Range Brochure
Zanussi Television Brochure 1982
Ferguson Videostar Review
She soon put that down
1983 Sanyo Brochure
Wireless World Teletext Decoder
Unitra Brochure
Rediffusion CITAC (MK4A)
Thorn TRUMPS 2
Grundig Brochure 1984
The Obscure and missing Continental
G11 Television 1978 – 1980
Reditune
Hitachi VIP201P C.E.D Player
Thorn 3D01 – VHD VideoDisc Player
Granada Television Brochure, 1970s
Long Gone UK TV Shops
Memories of a Derwent Field Service Engineer
PYE Australia Circa 1971
Radios-TV VRAT
Fabulous Fablon
Thorn TX10 Chassis
Crusty-TV Museum, Analogue TV Network
Philips N1500 Warning!
Rumbelows
Thorn EMI Advertising
Thorn’s Guide to Servicing a VCR
Ferguson 3V24 De-Robed
Want to tell us a story?
Video Circuits V15 – Tripler Tester
Thorn Chassis Guide
Remove Teletext Lines & VCR Problems
Suggestions
Website Refresh
Colour TV Brochures
1970s Lounge Recreation
CrustyTV Vintage Television Museum
Linda Lovelace Experience
Humbars on a Sony KV2702
1972 Ultra 6713
D|E|R Service “The Best”
The one that got away
Technical information
Test Equipment Altai PP-245
Does anyone have a diagram for this regulated power supply I believe it’s based on the LM723 & 2N3055 transistors the IC is missing & various cables are cut removed , Electrovision no longer have any service info on this model or any from this period. Any help appreciated
Didn't all CB power supplies run on the same chip and transistor.
You could likely work it out from the datasheet for the 723, which I seem to recall had a diagram for just such a supply.
I have the ALTAI PP-243, does this look similar?
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Similar, but not the same Chris - the OP's would be a 5A unit, here's an example:
https://www.ppauctions.com/archived-lots/109917/lot-532/altai-pp245-psu-0-24v-5a-t124-lot-located-a
Yours seems to use (possibly) a dual op-amp for the error amplifier.
@crustytv Hello thank you for taking the time to photograph the inside of your power supply. From the outside the unit is identical but mine has a vertical PCB with a larger IC which I’m assuming is the LM723 . In your workshop I noticed you have a little Eagle PSU this uses the same IC & a diagram would be handy if you have one. I’ve got various LM723 diagrams from google but they seem to differ on the pin connections hence why a diagram for the PP-245 would confirm the IC type.
Posted by: @arelectricalIn your workshop I noticed you have a little Eagle PSU this uses the same IC & a diagram would be handy if you have one.
Hi you'll have to forgive me, but I have no idea what you mean "Eagle PSU", I have just two PSU's (see below) one linear, the other SMPS. Can you point me to the photo you've looked at? The only other PSU I had was a Philips, which I passed on to another member a good few years ago.
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@arelectrical LM723 pinouts naturally vary between the plastic DIP version, the metal can version which has fewer leads and the surface mount version. Get the datasheet direct from TI and if it is a 723, you can work it out from that but frankly, if the PSU has been butchered in the manner you describe I'd bin it and look for something like a Farnell L30/5 to replace it.
@cathovisor Hello yes indeed I have a Farnell L30. This Altai power supply is just a project which I’m hoping I can get to the bottom of
@cathovisor yes it dos use a dual op amp with a reference voltage of 7v
That's the Altai PP-243, as shown in post #4 above, when it used to live on the store room test bench.
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@cathovisor Yes that’s the one. It uses the LM723 the same as the PS I’m working on
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