Hi Gerhard,

ich habe mal Gerardo befragt. Seine Antwort:

"You should not use a DC power supply with any Fidelity chess computer that has speech. You need AC not to obtain the DC 5V for the digital electronics, but to obtain (from the sine wave) -12V and +12V approximately, which are used for the speech synthesiser. That is, in these chess computers there are two internal power supplies, not just one for DC 5V.

If you use an external DC power supply, some Fidelity chess computers with speech will work (obviously without speech) and others will freeze. This depends on the design, on a feedback signal that the speech synthesiser chip sends to the microprocessor and on the software's use of this signal."

Danke Gerardo. Gut zu wissen.

Gruß
Micha