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Kai Klaas
02/09/06 19:46
Modified:
  02/09/06 19:56

Read: 529 times
Germany


 
Msg Score: +1
 +1 Informative
#109666 - Combine
Responding to: U Kaz's previous message
Kaz said:
Could someone please suggest how can I solve this problem?

The very simplest methode would be to have a resistor permanently connected across storage cap, like this is done in some stage amps and similar, where also big storage caps are used. Unfortunately, much heat is produced, if a fast fall down of potential is wished.
How long may the fall down of potential last? Why is a fast fall down needed at all?

Doing switchings by the help of a relay is a bit troublesome, because contacts can enormously suffer from sparkings.

A good methode would be to combine the turn-off of power supply with the turn-off of motor by additional soft- or hardware: When you want to turn-off the power supply, first turn-off the motor. Then there will be no further current flow and the power supply to motor can be disconnected without sparking.
Turning-off power supply should turn-off both, (a) mains from primary side of transfomer and (b) connection between storage cap and motor. Use two separate relays for this.

By the way, it's not a good idea to always discharge the storage caps, when switching-off the power supply. Keeping the storage caps charged can be advantageous.

Also, do you already need a soft start, when switching the transformer to mains? I guess so.

Kai

List of 19 messages in thread
TopicAuthorDate
Discharging capacitors?      U Kaz      02/09/06 09:17      
   sorry I missed that..      U Kaz      02/09/06 09:35      
   many versions have been implemented      Erik Malund      02/09/06 09:40      
      Simplest        Andy Neil      02/09/06 09:55      
         Alternatively...      Hal Albach      02/09/06 12:23      
            Switch      Andy Neil      02/09/06 12:32      
         thankyou      U Kaz      02/10/06 01:39      
            Emergency stop      Per Guldmann      02/13/06 10:21      
            Soft start      Kai Klaas      02/13/06 19:34      
   Combine        Kai Klaas      02/09/06 19:46      
      if it has to be done the right wa      Erik Malund      02/10/06 06:36      
         SPS?      Kai Klaas      02/10/06 07:25      
            if a SPS is a switching power supply - y      Erik Malund      02/10/06 08:13      
      resistor value ??      U Kaz      02/13/06 08:53      
         DIY      Steve M. Taylor      02/13/06 17:02      
            Hmm...      Kai Klaas      02/14/06 20:11      
               the crux      Erik Malund      02/15/06 06:19      
   check current rating of capacitors ...      Frieder Ferlemann      02/13/06 09:13      
      search      Saif Ullah Khalid      02/14/06 09:13      

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