Good morning, I posted last week about those Sony's I found and repaired, and now I have something for slight discussion- Instant-On. The '77 KV1712 has a badge called 'Econoquick' on the front below the tube, and I cant help but notice how, if it is instant-on, it doesnt seem to function. My theory is that its just a slow one, because the filament is lit. This is all the more reason to disable the feature.
I seem to remember how you could wire in a new switch which disables the circuit, or use an inline switch, but I would like to actually remove whatever it is which lights the crt heater and never have to worry about this again.
I am this critical because I now did some work to the chassis, including replacing many capacitors and some reistors, and set rgb backgrounds and greyscale, which resulted in a great pix.

My only other set right now with instant-on is a 1974 Panasonic 12" SS portable, believe it or not. Nice set, with removable front screen cover, labeled "Speed-o-Vision". It really does snap to life, but since I rarely use that one, I can just unplug it. Thanks for any ideas. Have a good one.

The Econoquick is a "half-way" instant on. It keeps a couple volts on the filaments, but not full blast like Zenith did on the 25DC56/EC58, and Hitachi did also on some early 70s sets. So it's normal for a couple seconds of warmup even with Econoquick. There wasn't a switch for Econoquick, however the remote sets had a "vacation" main switch on some models which killed the whole AC line to the set. I know the early big screens of the early 70s such as the KP-4000 and its ilk had them, and I think the KV-xx30, KV-xx41 sets did too.

I like Econoquick because it seems to make the CRT last longer (debated in another thread a few months ago). My experience is that on those Sonys, the tube can be in great shape, then if you unplug the set for 6 months, the CRT looks terrible. To racap that other thread, my theory is that the slight heat in the tube will keep the gasses at bay, and no allow the cathode coating to get corroded as easily.

To disable it, I would think the easiest would be to add a relay to the filament circuit which would open with no B+ applied. I got rid of all my Sony books, or I'd be able to give a better answer. I do recall that there are 4 wires on the ON-OFF switch, which probably has something to do with the Econoquick.

Charles

Thanks for that info, Charles. Based on your post, I may just leave the econoquick alone, and leave it plugged in. I still don't know why its supposed to be such a design so that it takes a few seconds- Because full blast on would cut tube life? Maybe this is the type of instant-on I was afraid of. Leave it to Sony to actually design something useful .... Anyway thanks again

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I'm almost sure "Econoquick" was when they completely stopped using instant on. The explanation was that their new CRT design warmed up quickly without using any power when the set was off. I could be wrong, but I never noticed the heaters staying hot on any Econoquick set I saw. Before the Econoquick sets, they kept the CRT heaters at about half power when the set was off.

Now my curiosity is aroused... I'll look at a few Sony schematics and see if I can come up with an answer.

Charles

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I know Sony used a direct heated filament cathode (no cathode sleeve) on the crt some of their small b/w sets for very quick crt warmup...I guess they couldn't have really used that on the Trinitron could they?

I know Sony used a direct heated filament cathode (no cathode sleeve) on the crt some of their small b/w sets for very quick crt warmup...I guess they couldn't have really used that on the Trinitron could they?

Interesting. I don't know, but I wouldn't think a filament cathode would give a very good spot, so maybe it was just OK for small B&W tubes.

I don't know about Sony, but I do remember CRTs going to quick-warmup cathodes in place of instant-on. The quick warm-ups could come on in about 12 seconds (vs. 20 seconds or more in the old sets). Of course, the benefit is only in a solid-state chassis where you are not waiting for a whole bunch of other tubes to warm up.

Yeah, I have a 1978 Admiral 12" black and white solid state tv that claims to utilize a "quick-heater" crt - It in fact comes up from cold in about 8 seconds, yet It definitely does not appear to be instant-on. This conforms to what old tv nut said

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The 5" Sony color sets (KV-5000, 5100, 5200) use directly heated cathodes. There are 3 filament transformers on the CRT board which supply each filament with its own isolated supply. They warm up in well under 5 seconds.
Very interesting!