HP-43120A defibrillator PS
Hello,
I'm looking for the schematic of this medical instrument or even only the schematic of its power supply board (HP 43100). The switching mosfet is arcing between drain and source until a resistor fuses on the 220V AC line (usually a couple of zeners around the mosfet driver BJT go short too). I checked the snubber part of the circuit and it tests ok. The schematic would tell me if arcing interrupted one or more hidden traces around the mosfet circuit. D-S arcing sounds like no current recirculation, doesn't it? Thanks in advance Francesco |
HP-43120A defibrillator PS
On Feb 17, 8:09 am, wrote:
Hello, I'm looking for the schematic of this medical instrument or even only the schematic of its power supply board (HP 43100). The switching mosfet is arcing between drain and source until a resistor fuses on the 220V AC line (usually a couple of zeners around the mosfet driver BJT go short too). I checked the snubber part of the circuit and it tests ok. The schematic would tell me if arcing interrupted one or more hidden traces around the mosfet circuit. D-S arcing sounds like no current recirculation, doesn't it? Thanks in advance Francesco A common failure on that supply is high esr capacitors. Beyond that, you cannot get any component level information on it. You won't get the schematic, it was board level replacement repair and HP never released them. |
HP-43120A defibrillator PS
On 17 Feb, 14:33, " wrote:
On Feb 17, 8:09 am, wrote: Hello, I'm looking for the schematic of this medical instrument or even only the schematic of its power supply board (HP 43100). The switching mosfet is arcing between drain and source until a resistor fuses on the 220V AC line (usually a couple of zeners around the mosfet driver BJT go short too). I checked the snubber part of the circuit and it tests ok. The schematic would tell me if arcing interrupted one or more hidden traces around the mosfet circuit. D-S arcing sounds like no current recirculation, doesn't it? Thanks in advance Francesco A common failure on that supply is high esr capacitors. Beyond that, you cannot get any component level information on it. You won't get the schematic, it was board level replacement repair and HP never released them. Thanks for info, I failed to mention that I also checked ESR of all electrolitics. The big ones are well below 0.5 ohm and the tiny axial 33 uF ones are below 2 ohm. It doesn't seem an ESR problem, unfortunately. But I'll recheck all just in case. Francesco |
HP-43120A defibrillator PS
|
HP-43120A defibrillator PS
This is a medicial lifesaving device to be used to restart a stopped
heart. As a retired biomed engineer I would not attempt a repair with no documentation available. Way too much lialibility involved and you want them to work everytime 100 percent. Board replacement is probably best. Hugh And yes I have had them used on me once. Still glad it worked. |
All times are GMT +1. The time now is 07:27 PM. |
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 DIYbanter