I made an external HDD caddy for 5 drives, the data is connected through Sata>USB>USB hub. The power takes one molex connector and splits it through 5 DPST switches that control the 5v and 12v, HDDs have a constant twin ground from molex. Any of the switches power(12v) a central fan through a diode (to protect the HDD from being switched on with back current from the fan). And each HDD has a red LED+resistor (maybe 450 ohms i forget) on the 5v in parallel with its HDD.
The problem; when 1 or more drives are on, and i turn another drive on the drive/s that were on are re-started. I think its because the voltage dips when a new drive is turned on and the other drives shut down for a second so they need to re-start.
Possible solution; I could put a smoothing capacitor in parallel with each drive (12v and 5v?), in theory they would charge up when the drive was powered up and protect the drive from voltage dips caused by other drives being powered up.
Any suggestions welcome, not sure what size of capacitors to use, or whether i risk damaging the drives
The problem; when 1 or more drives are on, and i turn another drive on the drive/s that were on are re-started. I think its because the voltage dips when a new drive is turned on and the other drives shut down for a second so they need to re-start.
Possible solution; I could put a smoothing capacitor in parallel with each drive (12v and 5v?), in theory they would charge up when the drive was powered up and protect the drive from voltage dips caused by other drives being powered up.
Any suggestions welcome, not sure what size of capacitors to use, or whether i risk damaging the drives