Safety in a box - UK Vintage Radio Repair and Restoration Discussion Forum

DON THOMSON · 9th Feb 2006, 1:01 pm

Hi
Having recently got a belt from a set whose chassis was live I decided to resurrect a simple piece of gear I had made years ago. Whilst hunting for it I came across another simple bit of kit and decided to build them into one unit. No unnecessary extra expenditure was to be made so the scrap boxes were raided and finally all I bought was an extra wide pattress box.

What is it for? Well it is not just a heap of junk looking for the role of extra in a new Frankenstein film. The thumbnail shows it indicating that the chassis of the DAC90A is live, as does thje horrible scream from the little siren, and that as the set warms up there is no short circuit or excess current draw - further the lamp gives a modicum of protection if anything goes pop.

Old timers and the not so old will recognise the two circuits but newcomers might find them of interest. Will provide more details if requested.

Cheers,

Don

Nickthedentist · 9th Feb 2006, 1:23 pm

Looks useful, Don

Paul also describes a similar "lamp limiter" here: http://www.vintage-radio.com/projects/lamp-limiter.html

My bench test socket, as well as being wired through an isolating transformer, has a chunky, unambiguous on/off switch and a red 15W pygmy lamp to indicate when it's powered. I like your idea of a buzzer/siren, but I suspect it could get a bit too annoying for me

Nick.

DON THOMSON · 9th Feb 2006, 2:22 pm

Hi Nick,

It sounds horrible, the tone is modulated at 100cps - so I put a muting switch in.

Cheers

Don

9th Feb 2006, 1:01 pm	#1
DON THOMSON Retired Dormant Member Join Date: Nov 2005 Location: CHELMSFORD, ESSEX,UK Posts: 26	Safety in a box Hi Having recently got a belt from a set whose chassis was live I decided to resurrect a simple piece of gear I had made years ago. Whilst hunting for it I came across another simple bit of kit and decided to build them into one unit. No unnecessary extra expenditure was to be made so the scrap boxes were raided and finally all I bought was an extra wide pattress box. What is it for? Well it is not just a heap of junk looking for the role of extra in a new Frankenstein film. The thumbnail shows it indicating that the chassis of the DAC90A is live, as does thje horrible scream from the little siren, and that as the set warms up there is no short circuit or excess current draw - further the lamp gives a modicum of protection if anything goes pop. Old timers and the not so old will recognise the two circuits but newcomers might find them of interest. Will provide more details if requested. Cheers, Don Attached Thumbnails

9th Feb 2006, 1:23 pm	#2
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,845	Re: Safety in a box Looks useful, Don Paul also describes a similar "lamp limiter" here: http://www.vintage-radio.com/projects/lamp-limiter.html My bench test socket, as well as being wired through an isolating transformer, has a chunky, unambiguous on/off switch and a red 15W pygmy lamp to indicate when it's powered. I like your idea of a buzzer/siren, but I suspect it could get a bit too annoying for me Nick.

9th Feb 2006, 2:22 pm	#3
DON THOMSON Retired Dormant Member Join Date: Nov 2005 Location: CHELMSFORD, ESSEX,UK Posts: 26	Re: Safety in a box Hi Nick, It sounds horrible, the tone is modulated at 100cps - so I put a muting switch in. Cheers Don