HI Velleman
My K4040 kit is up and running. But I am trying to understand the circuit relaed to the power on sequence. PLease can you clarify the following.
1 Are relays 1-5 shown in the enegised or deenergised condition.
2 When S1 is in the off condition I would expect RY3 conatcts to be open as shown in the diagram, i.e. no power is applied to trans02. Is this the case? If so is the relay energised or de-energised, from the circuit diagram I would expect it to be de-energised, using the normally open connections of R3. I would then expect RY3 to be energised with S1 in the standby and on conditions applying power to transf02 initially via R102-R106. However, this does not seem to fit if all relay conacts are shown in the energised condition, i.e. RY3 is denegised with S1 in the off condition and power is applied to transf02
2 RY1 and RY2 look to be energised when S1 is in the off condition via D20 once c26 is charged enabling the input signal to be connected to the amp,assuming that RY1 and 2 are shown in the enegised condition, no big deal as the amp isn’t powered but why? I would only expect RY1 and 2 to be enegised once S1 is in the on condition.
3 I assume RY4 is energised throughput the standby condition and following a short delay when S1 is in the on position de-energises to apply a short across R105, 6, 7 and 8. Also when S1 is set to on RY5 energises for a short period allowing R78 and R79 to limit in rush current then deenergises to apply a short across R78 and R79.
Sorry to be long winded but I have been trying to figure this circuit out for some time.
Thanks
Jeff