Enterprise Forever

:UK => Hardware => Topic started by: gflorez on 2014.January.24. 12:31:16

Title: colder replacement for LM7805
Post by: gflorez on 2014.January.24. 12:31:16
A few months ago, searching the Web, I found a switching power suply replacement for the hot 7805, the DE-SW050(Dimension Engenieering). It is only a little bigger than the  7805 IC and gives better characteristics whit the same pinout.

As a proof of concept I've installed it on a Spectrum, discarding the heatsink!, and it now works perfectly at ambient tempeature...


I've also replaced the regulator in my EXDOS card, now powering the HXC Floppy Emulator.



For now I will not change the internal regulator of my EP, as I fear for the keyboard membrane keyboard. (I already broke them  on the Spectrum and  had to put a new one)


On the other hand it cost each 15$ (+1.25$ shipping) but I think is a good investment in our loved machines to get them more cold....

This is the Web page of the company where they sell worldwide:

http://www.dimensionengineering.com/products/de-sw050
Title: Re: colder replacement for LM7805
Post by: jltursan on 2014.February.01. 00:25:41
I've been always searching for better, colder & cheap 7805 replacements. This one looks great; but I still think that the Tracopower (http://www.newark.com/tracopower/tsr-1-2450/dc-dc-conv-non-iso-pol-1-o-p-1a/dp/08R5932?MER=PPSO_N_C_EverywhereElse_None) is the perfect choice. It also seems to be cheaper, about $9 each :-)
Title: Re: colder replacement for LM7805
Post by: gflorez on 2014.February.01. 01:25:38
You're right, I didn't know that.

I bought a few of the other so, I'll keep that reference.


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Tienes razón, no conocía ese.

He comprado unos cuantos del otro, , así que guardaré la referencia.


Gracias. ¿Donde los compras?
Title: Re: colder replacement for LM7805
Post by: szipucsu on 2014.February.01. 12:15:57
(OFF topic: Write your posts both in English and in Spanish, I like reading them in both languages!
Escribid vuestros mensajes en inglés y español también, me gusta los leer en ambas lenguas. )
Title: Re: colder replacement for LM7805
Post by: gflorez on 2014.February.01. 14:40:30
No problem with me. 

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Por mi no hay problema.
Title: Re: colder replacement for LM7805
Post by: dolargaan on 2014.February.01. 14:49:43
Quote from: jltursan
I've been always searching for better, colder & cheap 7805 replacements. This one looks great; but I still think that the Tracopower (http://www.newark.com/tracopower/tsr-1-2450/dc-dc-conv-non-iso-pol-1-o-p-1a/dp/08R5932?MER=PPSO_N_C_EverywhereElse_None) is the perfect choice. It also seems to be cheaper, about $9 each :-)
This is my solution.  The step-down converter about 1.4$ from ebay.
Title: Re: colder replacement for LM7805
Post by: jltursan on 2014.February.03. 23:00:34
Beware that cheap chinese DC-DC converters, they'are far from good and usually lack of extra safety circuitry. They usually tend to generate a lot of noise in the 5V line...
Title: Re: colder replacement for LM7805
Post by: dolargaan on 2014.February.03. 23:18:22
Yes, I had an experience with this. I had to build one plus 1000uF to the motherboard, to keep noise below 20mV.  After all, it seems to works well.