1024MAK wrote:Now, I've not yet tried any of these yet, but on some other machines (e.g. Spectrums and ZX81's) some people have fitted switch mode converters like Traco DC-DC Converters TSR-1 Series 1 A or RECOM R-78Bxx-1.0 DC/DC-Converters.
Mark
We (German ZX-Team) use those switching regulators like the recom in our ZX80 replicas and ZX81s.
There are also (at least two) other producers. Recom is the "oldest".
The picture from ZX81s are quite sensitive to noise (ripple from the switching) on the VCC, someone found out that a small coil between the 5V Output of the recom and the mainboard minimizes this.
for more info look
here. The size of the coil needed corresonds to the current drawn
In case of lingual problems google translator may be helpful. If that is not sufficient, do not hesitate to ask.