Guest guest Posted December 29, 2003 Report Share Posted December 29, 2003 Most of us techs and engineers are well aware that more than 5 milliamps of current flowing through the body is deadly. This is fact, not speculation. If you use the formula A= V/R, then 5V divided by 10,000 Ohms (a very low value for skin resistance) would be only 500uA (0.5mA). The zapper does not have a 9V output - that is the battery voltage. You don't divide by the value of the series resistor (in the zapper). That's saying that our bodies skin resistance is zero! It's best not to get too involved in these discussions if you don't understand electronics. I wasn't implying that you shouldn't use any of these devices. Just get a little annoyed when people give specs which are so far off conserning an instrument which is wired to your body. BTW, if people believe that 8mA is OK, then they may make a very serious mistake in the future. Yes, these facts can be very important. Someone needed to straighten this out. " Secondly, if skin resistance is too j> high to allow a current of 8 ma to pass at an applied voltage of 12V j> then surely Bil's concern about the potential hazard of such a j> current does not exist because of the inherent current limiting j> ability of the top layer of skin. " Just to make this more clear, it was you that said the output is 8mA, not me. -- Best regards, Bil Green 2001 TV VCR Mammoth Lakes, CA 93546 mailto:tv.vcrrepair@... Sunday, December 28, 2003, 8:37:44 PM, you wrote: j> Re Bil's terse reply to my post. I point out that his claim that 8ma j> output " would be deadly " is rather curious. Hulda e's original j> zapper used a 1000 ohm limiting resistor on the output of a 555 IC j> which was powered by a 9 V battery. The math calculates output j> pulses of near 9 ma from that device.This zapper design was probably j> made bt thousands uf users. I have heard no reports of uses dropping j> dead from using that zapper. Secondly, if skin resistance is too j> high to allow a current of 8 ma to pass at an applied voltage of 12V j> then surely Bil's concern about the potential hazard of such a j> current does not exist because of the inherent current limiting j> ability of the top layer of skin. All a bit hysterical Bil. j> Joni. Quote Link to comment Share on other sites More sharing options...
Guest guest Posted January 1, 2004 Report Share Posted January 1, 2004 > Most of us techs and engineers are well aware that more than 5 > milliamps of current flowing through the body is deadly. This > is fact, not speculation. > > If you use the formula A= V/R, then 5V divided by 10,000 Ohms > (a very low value for skin resistance) would be only 500uA > (0.5mA). The zapper does not have a 9V output - that is the > battery voltage. > > You don't divide by the value of the series resistor (in the > zapper). That's saying that our bodies skin resistance is > zero! It's best not to get too involved in these discussions > if you don't understand electronics. > > I wasn't implying that you shouldn't use any of these devices. > Just get a little annoyed when people give specs which are so > far off conserning an instrument which is wired to your body. > > BTW, if people believe that 8mA is OK, then they may make a > very serious mistake in the future. Yes, these facts can be > very important. Someone needed to straighten this out. > > " Secondly, if skin resistance is too > j> high to allow a current of 8 ma to pass at an applied voltage of 12V > j> then surely Bil's concern about the potential hazard of such a > j> current does not exist because of the inherent current limiting > j> ability of the top layer of skin. " > > Just to make this more clear, it was you that said the output > is 8mA, not me. > > -- > Best regards, > > Bil Green > 2001 TV VCR > Mammoth Lakes, CA 93546 > --- ------------------------------------------------------------------- My point re the zapper was this - I have built several a few years ago and my notes indicate that at the pad skin area a peak to peak voltage of 2 Volts is present ( I have a oscillogram photo record in the notes). Therefore( assuming an output voltage swing at pin3 of the LM555 of about 8 volts)a voltage drop of 6 volts is across the 1000 ohms series resistor( Ik ohm was the original value that published). Then this calculates to current pulses of 6 ma passing through the resistor and further onward into the body. I again remind you that probably tens of thousands of these 'zappers' were constructed and I would think that we would have heard of any " deadly " consequences of their use. Possibly someone else has some comment on this point about pad current ? Joni. Quote Link to comment Share on other sites More sharing options...
Guest guest Posted January 2, 2004 Report Share Posted January 2, 2004 I am sorry if this sounds rude, I don't mean to be, but you obviously don't understand electrical or electronics circuits (or understand/read my replies). The series resistor is also in series with YOUR BODY. Your bodies resistance is not zero ohms. I could have replied to you directly if you hadn't posted this incorrect information to the list. As I indicated earlier, it is best to avoid these discussions if you are not familiar with the subject. Study Ohms law or take a course in basic electronics. Current flow is always equal in EVERY part of a series circuit (including your body in this case, which has a much higher resistance than 1,000 ohms). -- Best regards, Bil Green 2001 TV VCR Mammoth Lakes, CA 93546 mailto:tv.vcrrepair@... Thursday, January 1, 2004, 6:40:44 AM, you wrote: j> >> Most of us techs and engineers are well aware that more than 5 >> milliamps of current flowing through the body is deadly. This >> is fact, not speculation. >> >> If you use the formula A= V/R, then 5V divided by 10,000 Ohms >> (a very low value for skin resistance) would be only 500uA >> (0.5mA). The zapper does not have a 9V output - that is the >> battery voltage. >> >> You don't divide by the value of the series resistor (in the >> zapper). That's saying that our bodies skin resistance is >> zero! It's best not to get too involved in these discussions >> if you don't understand electronics. >> >> I wasn't implying that you shouldn't use any of these devices. >> Just get a little annoyed when people give specs which are so >> far off conserning an instrument which is wired to your body. >> >> BTW, if people believe that 8mA is OK, then they may make a >> very serious mistake in the future. Yes, these facts can be >> very important. Someone needed to straighten this out. >> >> " Secondly, if skin resistance is too >> j> high to allow a current of 8 ma to pass at an applied voltage j> of 12V >> j> then surely Bil's concern about the potential hazard of such a >> j> current does not exist because of the inherent current limiting >> j> ability of the top layer of skin. " >> >> Just to make this more clear, it was you that said the output >> is 8mA, not me. >> >> -- >> Best regards, >> >> Bil Green >> 2001 TV VCR >> Mammoth Lakes, CA 93546 >> --- j> ------------------------------------------------------------------- j> My point re the zapper was this - I have built several a few j> years ago and my notes indicate that at the pad skin area a peak to j> peak voltage of 2 Volts is present ( I have a oscillogram photo j> record in the notes). Therefore( assuming an output voltage swing at j> pin3 of the LM555 of about 8 volts)a voltage drop of 6 volts is j> across the 1000 ohms series resistor( Ik ohm was the original value j> that published). Then this calculates to current pulses of 6 j> ma passing through the resistor and further onward into the body. j> I again remind you that probably tens of thousands of j> these 'zappers' were constructed and I would think that we would j> have heard of any " deadly " consequences of their use. j> Possibly someone else has some comment on this point about pad j> current ? Joni. Quote Link to comment Share on other sites More sharing options...
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