Analogue Computing - UK Vintage Radio Repair and Restoration Discussion Forum

HMV 1120 · 13th Dec 2007, 11:03 pm

Just an idea that has been floating around in my head for a few days. Is it feasible to build a simple analouge computor with a minimum of materials? I was thinking of something that could do simple calculations or conversions (e.g waveband to KHZ via rotating two potentimeters. An LED lights when each is at the correct value)with the aid of an IC or several transisters, with output being shown via LEDs or a buzzer tone.

Am I crazy? (probably

) Any thoughts much appreciated.

All the best, Rob.

GMB · 14th Dec 2007, 12:13 am

The building blocks for real analogue computing are now available as simple ICs so it has never been easier or cheaper to build a really quite complex one.

I don't think lighting a light is at all in the spirit of the analogue computer – that's digital!!

Marconi Man · 14th Dec 2007, 9:23 pm

I still have my Practical Electronics analogue computer that I buiilt in the late 60s!!

It hasn't got a blinking LED any where near it!!

John.

HMV 1120 · 14th Dec 2007, 10:33 pm

*Ups hands* Okay! Hang fire! I surrender! No LEDs, I promise! I won't build an intelligent christmas tree!

Would it be an idea to breadboard a few simple, fixed function circuits first - or build several seperate 'blocks' that can be 'programed' by the judicious use of crocidile leads? Has anyone ever actually done this before?

Yours curiously, Robs.

GMB · 14th Dec 2007, 11:46 pm

I suggest you start with a dual stabilised power supply and then op-amps are nice and easy. Then you just need a load of sockets and a few pots. If you can still get the very small sockets (1 or 2mm?) you can just plug actual resistors directly into them.

Multipliers are available but be aware that they are prone to noise and instability.

Ed_Dinning · 16th Dec 2007, 7:27 pm

Hi Robs, Horowitz & Hill, "The Art of Electronics", which is a first year university text book has plenty of details on op amps and analogue computing. There are also some specialist papers from Teledyne Philbrick, who produced a large range of special function computing "blocks" in the 70's.

Ed

HMV 1120 · 16th Dec 2007, 9:52 pm

Thankyou guys. Will start ordering components after christmas - we'll see what I cook up. (Burning solder on the carpet, most likely! ^^)

13th Dec 2007, 11:03 pm	#1
HMV 1120 Hexode Join Date: Jan 2007 Location: Weeting, Norfolk. Posts: 465	Analogue Computing Just an idea that has been floating around in my head for a few days. Is it feasible to build a simple analouge computor with a minimum of materials? I was thinking of something that could do simple calculations or conversions (e.g waveband to KHZ via rotating two potentimeters. An LED lights when each is at the correct value)with the aid of an IC or several transisters, with output being shown via LEDs or a buzzer tone. Am I crazy? (probably) Any thoughts much appreciated. All the best, Rob. __________________ Real radios glow in the dark M6GLD

14th Dec 2007, 12:13 am	#2
GMB Dekatron Join Date: Aug 2003 Location: near Reading (and sometimes Torquay) Posts: 3,095	Re: Analogue Computing The building blocks for real analogue computing are now available as simple ICs so it has never been easier or cheaper to build a really quite complex one. I don't think lighting a light is at all in the spirit of the analogue computer – that's digital!!

14th Dec 2007, 9:23 pm	#3
Marconi Man Retired Dormant Member Join Date: Jun 2005 Location: Luton, Bedfordshire, UK. Posts: 9	Re: Analogue Computing I still have my Practical Electronics analogue computer that I buiilt in the late 60s!! It hasn't got a blinking LED any where near it!! John.

14th Dec 2007, 10:33 pm	#4
HMV 1120 Hexode Join Date: Jan 2007 Location: Weeting, Norfolk. Posts: 465	Re: Analogue Computing Ups hands Okay! Hang fire! I surrender! No LEDs, I promise! I won't build an intelligent christmas tree! Would it be an idea to breadboard a few simple, fixed function circuits first - or build several seperate 'blocks' that can be 'programed' by the judicious use of crocidile leads? Has anyone ever actually done this before? Yours curiously, Robs. __________________ Real radios glow in the dark M6GLD

14th Dec 2007, 11:46 pm	#5
GMB Dekatron Join Date: Aug 2003 Location: near Reading (and sometimes Torquay) Posts: 3,095	Re: Analogue Computing I suggest you start with a dual stabilised power supply and then op-amps are nice and easy. Then you just need a load of sockets and a few pots. If you can still get the very small sockets (1 or 2mm?) you can just plug actual resistors directly into them. Multipliers are available but be aware that they are prone to noise and instability.

16th Dec 2007, 7:27 pm	#6
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,194	Re: Analogue Computing Hi Robs, Horowitz & Hill, "The Art of Electronics", which is a first year university text book has plenty of details on op amps and analogue computing. There are also some specialist papers from Teledyne Philbrick, who produced a large range of special function computing "blocks" in the 70's. Ed

16th Dec 2007, 9:52 pm	#7
HMV 1120 Hexode Join Date: Jan 2007 Location: Weeting, Norfolk. Posts: 465	Re: Analogue Computing Thankyou guys. Will start ordering components after christmas - we'll see what I cook up. (Burning solder on the carpet, most likely! ^^) __________________ Real radios glow in the dark M6GLD