Why does this configuration burn the L7808ABV voltage regulator ?

[EHarr.2]

I am having trouble with these linear voltage regulators and I have been able to isolate the problem in this simple circuit. In the attachment, you will see that I have two 4.7 microfarad capacitors in place between Vin (24 V) and Ground and Vout (8V for this regulator) and Ground. I added a safety diode between Vin and Vout in case the Vout pin is transiently above the Vin so that the current does not have to pass through the regulator. The input voltage (24 V) is applied through a switch that delivers the 24 V to the Vin pin when in the ON position, or shorts the Vin pin to Ground in the OFF position. I see that shorting Vin and Ground when powering down shorts the discharge capacitor, but shouldn't the 1N4001 compensate for this design issue ? If not, can someone please suggest a solution ? Basically after 4 cycles of powering on and off the regulator, there is no longer 8 V on the Vout pin and it is just putting out Vin.

[Tesla DeLorean]

Where would other voltages on VOUT be coming from?

How would they be HIGHER than VIN?

Wouldn't the DIODE be a conductive path to ground when you switch it off?

[EHarr.2]

Hi, Thanks for your reply.

1) In this configuration, there is nothing connected to Vout besides the discharge capacitor.

2) If the power is shut off abruptly with the switch, Vin is directly shorted to Ground. If the Vout pin discharges slowly through the capacitor, there is a short time where Vout > Vin.

3) Yes, I do not understand why the diode cannot protect my regulator...

[MM..1]

Simply switch out 24V without connect to gnd Vin.

And is killed 7808 or 1N4001 ???

[EHarr.2]

It kills the L7808.

the diode is ok..

[EHarr.2]

Hi, Thanks for your reply.

1) In this configuration, there is nothing connected to Vout besides the discharge capacitor.

2) If the power is shut off abruptly with the switch, Vin is directly shorted to Ground. If the Vout pin discharges slowly through the capacitor, there is a short time where Vout > Vin.

3) Yes, I do not understand why the diode cannot protect my regulator...

[EHarr.2]

this was meant to reply to first comment, i pasted it above