NOSTALGIA

Deltavision TV Repair

Important notice from Deltavision TV
In order to avoid catching (and spreading) Coronavirus (COVID 19) and to minimise any risk to my valued customers and my family, the following steps are being taken.


Deltavision TV is now open for business but with careful measures in place.


You can still contact me in the usual way, either by phone, SMS, Facebook messenger, or by using the contact page.


I will be happy to take in any repairs you may have, but every precaution will be taken regarding prevention of spread of the COVID 19 virus.


You are welcome to bring your faulty TVs VCRs DVDs etc but please phone first.


These items will then be carefully wiped down thoroughly with a suitable mild disinfectant on delivery to me, and again when you collect them.
The disinfectant has been tested on many surfaces and products with no adverse effects to their surfaces, but if you have concerns about this, please do not bring them.


Thank you for your co-operation in these awful times, but I am sure if we all act responsibly and follow central government guidelines, we will eventually see the end of this.


Please be assured, if I or any of my family show any of the symptoms of COVID 19 infection, we will self-isolate and business will close immediately.


To all my customers, please stay safe!


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Boselli Icon 30 modification

I was asked by a customer if I could provide him with a “power supply” for his circa 1970’s Italian ‘Boselli Icon 30’ (see picture) flip digital clock.


On examination of the clock, (which is entirely mechanically/ electromagnetically operated) needed a +24v pulse for first “flip”, followed a minute later by a -24v pulse, followed for the next cycle by a +24v pulse, and so on...


I said “yes I can do that for you”!


Originally I planned to use a NE 555 timer in astable mode set for 1 minute alternate “states”, but this would not have been anywhere accurate enough.


I explored many possibilities using crystal and logic division etc, but time was at a premium, as I’m really busy with my repair work, and this would have made things a bit too expensive for the project in hand.


I quoted the customer an acceptable price and set to work.


I decided to use a mechanical “trigger” from a cheap quartz clock movement. I firstly removed the fingers and replaced them with a revolving lightweight disc of plastic mounted on the SECOND HAND central spindle, with a 3mm hole drilled in the edge, and positioned a photo interrupter arrangement either side of the hole in the disc, so the disc revolves once per minute.


I now had a quartz controlled trigger, exactly one pulse per minute!


The electronic schematic comprises a two stage system plus the power supply.


The first stage includes the photo interrupter, which once per minute provides a positive pulse to switch the (normally hard on) PNP relay driver TR1 off briefly.


This de-energises the relay RLA2 breifly, the contacts are arranged to trigger the NE555 timer, which is in bistable mode, to “flip” to its “other” state, whether the output is a positve, or off output denotes the on or off state of the relay RLA1.


When the relay RLA1 is in one state the “Flip clock contacts” are reversed, compared to the “other state” where the contacts are non reversed.


Resulting output is + 1min  - 1min + 1min – 1min and so on!!


I’m fairly sure there’s a few of these clocks around, I wonder how many are redundant due to a missing trigger unit, and what did the original trigger unit comprise of?  I think maybe it was a mechanical unit, but does anyone know?

I’d love to know!


Here's my schematic diagram



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We repair TV, LCD TV repair, LED TV repair, Plasma TV repair, Audio system repairs, HIFI repairs, DVD repairs, and most electronic repairs.

We repair most makes and models of domestic electronic goods. All work is guaranteed.

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Colour bars
We repair the older CRT TVs also

If you have one of the earlier, CRT televisions,

we also service these too!