Keep in mind rise time (really - turn on time) doesn't mean much on the AC mains. Most specs assume the measurement is made right at the body of the device, so even short wires will add enough inductance for a fast wave to make the arguement moot.
> -----Original Message----- > From: Dan Kwok [SMTP:[email protected]] > Sent: Tuesday, January 11, 2000 11:09 PM > To: Ken Javor; EMC-PSTC Group > Subject: Re: transient suppression > > > Ken Javor wrote: > > > > When choosing transient suppression for power line input to equipment, > what > > are the choices (MOVs, silicon TVS, glass discharge tubes, others) and > what > > are the trade-offs? Thank you. > > Hello Ken, > > Here are some typical device types I've come across for transient > suppression: > > Varistors (MOVs): > Voltage Range 35 - 1400 V > Max. Current 50 - 100 A > Response Time 1 nsec > > Gas Discharge Tubes: > Voltage range 75 - 10,000 V > Max. Current 1000+ A > Response Time 1000 nsec > > Zener or Avalanche Diodes (lower voltage DC, Signal) > Voltage Range 5 - 200 V > Max. Current 1.5 - 10 A > Response Time 1 nsec > > Each device type has its own set of characteristics like polarity of > operation and failure mode. You may also need to consider the shunt > capacitance which can vary from 1pF to 100 nF depending on the device > type. Which type is best? It all depends on the specific application, > transient signal and the susceptibility of the equipment you are > protecting. It usually boils down to a trade-off between speed, size, > transient handling capacity and cost. > > > Hope that helps. > > Regards, > Dan > -- > ===================================================================== > Dan Kwok Vancouver, BC, Canada > Intetron Consulting, Inc. Telephone 604.432.9874 > > Email [email protected] > "FREE EMC Tips @ our website http://www.intetron.com"; > ===================================================================== > > --------- > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to [email protected] > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to [email protected], > [email protected], [email protected], or > [email protected] (the list administrators). > --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
