RE: Transient Voltage Suppressor - Europe approvals?
All: You are correct, but this is generally due to the cost of the TVS diode and the MOV, not the capability. Dave -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Peters, Michael Sent: Wednesday, June 19, 2002 1:51 PM To: Peters, Michael; 'emc-p...@majordomo.ieee.org' Subject: RE: Transient Voltage Suppressor - Europe approvals? I want to thank all those who replied for their responses. We have a lot to think over. To answer questions posed: The concept is to find an alternative to MOVs for surge protection. The attraction to the Transient Voltage Suppressors is their reliability and current clamping characteristics. General Semiconductor (now Vishay) does have a few mains rated, UL approved TVSs. They are rated to 120 VAC which doesn't make them useful for European voltages. The engineer I spoke with for Vishay informed me that they are contemplating UL approvals for their 400 and 440 TVSs up to those voltages. Based on the response, TVSs do not appear to be a popular method of transient protection on the power line. Thanks again, Michael Peters -Original Message- From: Peters, Michael Sent: Wednesday, June 19, 2002 9:33 AM To: 'emc-p...@majordomo.ieee.org' Subject: Transient Voltage Suppressor - Europe approvals? Greetings, Is anyone aware of Transient Voltage Suppressors (General Semiconductor calls them TransZorbs) with any European safety approvals (Semko, Demko, VDE, etc.,)? They would need to be rated for mains voltage. Thanks, Michael Peters --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Transient Voltage Suppressor - Europe approvals?
I want to thank all those who replied for their responses. We have a lot to think over. To answer questions posed: The concept is to find an alternative to MOVs for surge protection. The attraction to the Transient Voltage Suppressors is their reliability and current clamping characteristics. General Semiconductor (now Vishay) does have a few mains rated, UL approved TVSs. They are rated to 120 VAC which doesn't make them useful for European voltages. The engineer I spoke with for Vishay informed me that they are contemplating UL approvals for their 400 and 440 TVSs up to those voltages. Based on the response, TVSs do not appear to be a popular method of transient protection on the power line. Thanks again, Michael Peters -Original Message- From: Peters, Michael Sent: Wednesday, June 19, 2002 9:33 AM To: 'emc-p...@majordomo.ieee.org' Subject: Transient Voltage Suppressor - Europe approvals? Greetings, Is anyone aware of Transient Voltage Suppressors (General Semiconductor calls them TransZorbs) with any European safety approvals (Semko, Demko, VDE, etc.,)? They would need to be rated for mains voltage. Thanks, Michael Peters --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Transient Voltage Suppressor - Europe approvals?
Chris, Not sure what you may be experiencingas far as I know the site is public access. Another way to get there: 1) go to the UL homepage www.ul.com 2) select the link titled certifications on the left hand side of the page 3) use the keyword search or other tools available. Regards, Kaz -Original Message- From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Wednesday, June 19, 2002 1:37 PM To: kazimier_gawrzy...@exchange.dell.com; mpet...@analogic.com; emc-p...@majordomo.ieee.org Subject: RE: Transient Voltage Suppressor - Europe approvals? Kazimier, I tried the website in your reply below and got You are not authorized to view this site. Is there some kind of login method that must be used? Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | -Original Message- From: kazimier_gawrzy...@dell.com [SMTP:kazimier_gawrzy...@dell.com] Sent: Wednesday, June 19, 2002 12:44 PM To: mpet...@analogic.com; emc-p...@majordomo.ieee.org Subject: RE: Transient Voltage Suppressor - Europe approvals? Michael, No ready to go answer for you but a suggestion as to finding a supplier. Pick some company names off the UL Certifications on-line directory and search the web for their sites...might be product offerings with European approvals as well as North American. Go to the link below and plant TVSS (or other useful find term) under the keyword search. http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/index.htm Thompson Registry might be another source of company names. Regards, Kaz Gawrzyjal Dell Computer Corp. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Transient Voltage Suppressor - Europe approvals?
JPR: But remember Energy is the factor of Current, Voltage, and Time. From a protection stand-point, TVS components divert currents and clamp voltages. It is for this reason that they are used in the circuit, system. Of course for best results lower clamping voltage is desired. If the current is the same and the waveform the same, the voltage for a TVS diode is lower the energy is also lower, but who cares at least the circuit/system is protected. Dave -Original Message- From: j...@aol.com [mailto:j...@aol.com] Sent: Wednesday, June 19, 2002 11:08 AM To: hutch...@protek-tvs.com; robert_wil...@tirsys.com; mpet...@analogic.com; emc-p...@majordomo.ieee.org Subject: Re: Transient Voltage Suppressor - Europe approvals? In a message dated 6/19/2002, Dave Hutchins writes: Energy has nothing to do with the capability of the TVS device. It is also proven that the energy in the transient threat is not the energy dissipated in the TVS component, just ask any old timer even those at Harris. Hi Dave: I'm not sure I agree with you on this one, but perhaps the issue is simply one of semantics. The energy I referred to was the energy in the surge, not the protection device. For example, a gas tube can handle, without damage, surges of far higher energy than a Transzorb. If I recall correctly, MOVs can also typically handle surges of higher energy than a Transzorb. In the past, when I have used a Transzorb or comparable device, it was for tertiary protection inside a circuit that was already protected by other devices with the ability to handle much higher energy surges. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.com
RE: Transient Voltage Suppressor - Europe approvals?
Kazimier, I tried the website in your reply below and got You are not authorized to view this site. Is there some kind of login method that must be used? Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | -Original Message- From: kazimier_gawrzy...@dell.com [SMTP:kazimier_gawrzy...@dell.com] Sent: Wednesday, June 19, 2002 12:44 PM To: mpet...@analogic.com; emc-p...@majordomo.ieee.org Subject: RE: Transient Voltage Suppressor - Europe approvals? Michael, No ready to go answer for you but a suggestion as to finding a supplier. Pick some company names off the UL Certifications on-line directory and search the web for their sites...might be product offerings with European approvals as well as North American. Go to the link below and plant TVSS (or other useful find term) under the keyword search. http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/index.htm Thompson Registry might be another source of company names. Regards, Kaz Gawrzyjal Dell Computer Corp. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: Transient Voltage Suppressor - Europe approvals?
In a message dated 6/19/2002, Dave Hutchins writes: Energy has nothing to do with the capability of the TVS device. It is also proven that the energy in the transient threat is not the energy dissipated in the TVS component, just ask any old timer even those at Harris. Hi Dave: I'm not sure I agree with you on this one, but perhaps the issue is simply one of semantics. The energy I referred to was the energy in the surge, not the protection device. For example, a gas tube can handle, without damage, surges of far higher energy than a Transzorb. If I recall correctly, MOVs can also typically handle surges of higher energy than a Transzorb. In the past, when I have used a Transzorb or comparable device, it was for tertiary protection inside a circuit that was already protected by other devices with the ability to handle much higher energy surges. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.com
RE: Transient Voltage Suppressor - Europe approvals?
Hello: The question is not the energy handling capability, it is a matter of cost. You can purchase a TVS diode that has the same energy handling capability of the MOV, but the cost is much different. By the way, energy is not a good measure of the capability of a TVS component. The TransZorb has a lower clamping voltage than an MOV for the same peak pulse current and waveform. Therefore the calculated energy is lower in the TransZorb. Energy has nothing to do with the capability of the TVS device. It is also proven that the energy in the transient threat is not the energy dissipated in the TVS component, just ask any old timer even those at Harris. Dave -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of j...@aol.com Sent: Wednesday, June 19, 2002 9:51 AM To: robert_wil...@tirsys.com; mpet...@analogic.com; emc-p...@majordomo.ieee.org Subject: Re: Transient Voltage Suppressor - Europe approvals? In a message dated 6/19/2002, Bob Wilson writes: Transzorbs (or TVSs) are basically zener diodes that are rated for their energy absorption capability. Hello All: One thing to keep in mind is that the energy handling capability of a TransZorb is generally not very high compared to other devices such as gas tubes, MOV's, and sidactors. Michael, your original posting did not specify the intended application, but the reference to being rated for mains voltage makes me wonder if you are trying to protect from surges on an AC mains input. If so, I do not think that a TransZorb would have adequate energy handling capability. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.com
RE: Transient Voltage Suppressor - Europe approvals?
Michael: I worked at General Semiconductor for about 25 years. I do not know of any specific component safety standard for TVS diode components. The one that we, when at General Semiconductor, had to meet was the UL 497B for telecommunications. Generally, there is no safety standard for individual components. It depends on how they are connected in the circuit and their location, that is for creepage and clearance distances. These components are used on AC power, DC power and data lines. Their selection depends upon specific applications and the peak pulse current and waveform. These two conditions are the only threat conditions that are important. But it is location of the device in the circuit or system that might cause of concern for safety. Dave -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Peters, Michael Sent: Wednesday, June 19, 2002 6:33 AM To: 'emc-p...@majordomo.ieee.org' Subject: Transient Voltage Suppressor - Europe approvals? Greetings, Is anyone aware of Transient Voltage Suppressors (General Semiconductor calls them TransZorbs) with any European safety approvals (Semko, Demko, VDE, etc.,)? They would need to be rated for mains voltage. Thanks, Michael Peters --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Transient Voltage Suppressor - Europe approvals?
Agreed. But not all the devices you mention operate in the same way. In particular, Sidactors get their high apparent energy absorption because they crowbar the line being protected, to relatively near ground potential. They are basically energy-rated bidirectional breakover diodes (acting like self-triggered triacs). Thus, although the device handles high spike current, the voltage across it is very low during this period (thus power dissipation in the device is much lower). Devices operating off the AC line being protected by a sidactor, will see an interruption in their power supply (the AC line), as a result of the sidactor clamping it to near-zero volts. Because of the Sidactor's crowbar action, it is not likely acceptable as a normal AC line protection device (they are more commonly used to protect data and telecom lines). A transzorb or a MOV simply limits the rise of voltage to a small increment ABOVE nominal line voltage, hence the power dissipation will be much higher than with a Sidactor. But the benefit is that devices operating from the protected AC line will see no interruption in their power when a hit occurs. Bob Wilson TIR Systems Ltd. Vancouver. -Original Message- From: j...@aol.com [mailto:j...@aol.com] Sent: June 19, 2002 9:51 AM To: Robert Wilson; mpet...@analogic.com; emc-p...@majordomo.ieee.org Subject: Re: Transient Voltage Suppressor - Europe approvals? In a message dated 6/19/2002, Bob Wilson writes: Transzorbs (or TVSs) are basically zener diodes that are rated for their energy absorption capability. Hello All: One thing to keep in mind is that the energy handling capability of a TransZorb is generally not very high compared to other devices such as gas tubes, MOV's, and sidactors. Michael, your original posting did not specify the intended application, but the reference to being rated for mains voltage makes me wonder if you are trying to protect from surges on an AC mains input. If so, I do not think that a TransZorb would have adequate energy handling capability. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.com
Re: Transient Voltage Suppressor - Europe approvals?
In a message dated 6/19/2002, Bob Wilson writes: Transzorbs (or TVSs) are basically zener diodes that are rated for their energy absorption capability. Hello All: One thing to keep in mind is that the energy handling capability of a TransZorb is generally not very high compared to other devices such as gas tubes, MOV's, and sidactors. Michael, your original posting did not specify the intended application, but the reference to being rated for mains voltage makes me wonder if you are trying to protect from surges on an AC mains input. If so, I do not think that a TransZorb would have adequate energy handling capability. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.com
RE: Transient Voltage Suppressor - Europe approvals?
Michael, No ready to go answer for you but a suggestion as to finding a supplier. Pick some company names off the UL Certifications on-line directory and search the web for their sites...might be product offerings with European approvals as well as North American. Go to the link below and plant TVSS (or other useful find term) under the keyword search. http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/index.htm Thompson Registry might be another source of company names. Regards, Kaz Gawrzyjal Dell Computer Corp. -Original Message- From: Peters, Michael [mailto:mpet...@analogic.com] Sent: Wednesday, June 19, 2002 8:33 AM To: 'emc-p...@majordomo.ieee.org' Subject: Transient Voltage Suppressor - Europe approvals? Greetings, Is anyone aware of Transient Voltage Suppressors (General Semiconductor calls them TransZorbs) with any European safety approvals (Semko, Demko, VDE, etc.,)? They would need to be rated for mains voltage. Thanks, Michael Peters --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Transient Voltage Suppressor - Europe approvals?
Transzorbs (or TVSs) are basically zener diodes that are rated for their energy absorption capability. Since they are polar devices (i.e. diodes) they are useless on an AC line. Well, I suppose you could put two of them back to back, but this is not at all common. Typically, these devices are used to protect lower voltage DC busses. Higher voltage (line voltage) AC lines are most commonly protected by varistors (e.g. ZnO types). Bob Wilson TIR Systems Ltd. Vancouver. -Original Message- From: Peters, Michael [mailto:mpet...@analogic.com] Sent: June 19, 2002 6:33 AM To: 'emc-p...@majordomo.ieee.org' Subject: Transient Voltage Suppressor - Europe approvals? Greetings, Is anyone aware of Transient Voltage Suppressors (General Semiconductor calls them TransZorbs) with any European safety approvals (Semko, Demko, VDE, etc.,)? They would need to be rated for mains voltage. Thanks, Michael Peters --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
