The Cyrus Tuner voltage is too high for the facade lighting lamps, because the primary of the transformer is 220V, now we have 240V. I changed the lamps because they were burnt out. I replaced them with the same 12V 60mA lamps. So I need to lower the voltage which is currently 23V to 12V. I took the same diagram as the 317 already installed for other 5V, 13V and 24V use. I need your opinion, is this addition good? or do you have another solution other than a drop resistance.
Why not to try a capacitor in series with transformer primary to reduce input voltage to the proper value?
A 7812 is even simpler if all it does is feed the lamps. Even easier than that is a series Zener in the feed to bulbs. 12 volt at 400ma (so I'm assuming 6 or 7 bulbs in parallel) would need a Zener of say 2.7 or 3.9 volt and a 2 watt or higher rating.
You should also check the reservoir caps are not to near their marked voltage limits when running on 240v.
You should also check the reservoir caps are not to near their marked voltage limits when running on 240v.
Or even a resistor/s ... to make a total value of say 8.2 ohm 2 watt. The heat generation is the same whether resistor, Zener or linear regulator.
Pick the wrong value of capacitor and you make a resonant circuit which has the exact opposite effect in that it will raise the voltage.
Given the voltage is higher, it's likely potting stress on the other power supply components so I'd suggest a bucking transformer between the wall outlet and tuner.
Why pick it arbitrarily? Do the maths and no problem will be.
For a 10% voltage reactive loss, the capacitor reactance will have a value ten times bigger the reactance seen looking into the thansformer primary and its load. So condition necessary for resonance aren't given.
Moreover, still in case of some resonance can occur, it will be damped just by the transformer's loss plus the load resistance at the secondary multiplied by turns ratio squeared.
Please, catch books that they don't bite.
For a 10% voltage reactive loss, the capacitor reactance will have a value ten times bigger the reactance seen looking into the thansformer primary and its load. So condition necessary for resonance aren't given.
Moreover, still in case of some resonance can occur, it will be damped just by the transformer's loss plus the load resistance at the secondary multiplied by turns ratio squeared.
Please, catch books that they don't bite.
Run 1 bulb with a resistor , run the others in series 2 bulbs each.