Just a little tidbit. Two of those springy and twangy doorstop/bumpers mounted to a heavy base (or magnets also) make a great pair of helping hands for holding wire and terminals for soldering. You just have to bend and slip the wire/terminal into a section of the tightly wound spring. A decent sized base also will retain solder dropping also.
Thank you for your skills and the video. I just made one with a 5/20 ceramic resistor. I did not have braided 12 AWG so I used a strand of house 12. I made it long enough to bend the ends close enough for capacitor terminals. getting ready to change out magnetron on microwave.
I now this is a while back ,but that is a great tutorial.Thats what I am going to build/use. Story coming up ! Way back about 1954 I was 9 .(UK) We just had our first TV. It always had problems, and the repair guy was at our house about every couple of weeks.He would always come in and discharge a large capacitor (as I now know),before working on the set.And He always used a screwdriver.Being interested in all things mechanical and electrical.I just asked him if there were a way that it could be done slower, instead of getting that large “CRACK” His reply was “Son, when you have worked on WW2 Radar.This is chicken feed, back in those days they were “real men’s capacitors.” My young thoughts were Wow! If this gives a crack! what must “they” have done? From then on I thought he was an electronics God.
Update: used my tool tonight on old capacitor and new one received in mail. Used DMM to determine both capacitors were good but installed new one due to it being more in spec. Thank you again for your knowledge on this potentially dangerous equipment.
Zip ties the new and very improved duct tape. I don't use the music anymore unless I have a time lapsed segment then I use it as audio filler. Thank you for watching, commenting and the valuable feedback. I appreciate it greatly. All the best. 👍😀
You can just use a lamp to discharge any capacitor under say 150v. Connect the plug of the lamp to the capacitor leads with wire and turn the lamp on. The lightbulb will provide the needed resistance.
I have never done this with a lamp so I can't really recommend it. I know what the resistance value is for my resistor but I can't guarantee the resistance of a random lamp. Thanks
a 60 watt lightbulb on a 120v power source means it runs with .5 amps based on ohms law. This means its resistance is 240 ohms. So it is a 240 ohm resistor rated for 60 watts. The lamp is not relevant here it is the bulb that is relevant. The prongs of the lamp are just the attachment interface making the discharge easier.
Hello Richard, greetings from the Philippines, just finished watching this video, it is very informative, I have question, what I have right here is a 2W 39 Ohm ceramic resistor that I can get from a spare electric fan board, is this value of R can be used as a replacement. We are still on a lockdown we cannot go out and stores are still closed.. Looking forward..
Great video...thx for posting. Couple questions 1) How do you calculate the resistor wattage rating needed to safely handle a given capacitor? 2) Can you put an LED in-line to verify the energy is draining/drained.
I aim for a 30 to 45 second discharge time as I know that will not harm the capacitor. Here is the calculator I used www.learningaboutelectronics.com/Articles/Capacitor-discharge-calculator.php#answer as you can see the resistor value will vary as the value of the capacitor changes. Play with the equation to see what best works for you. You could build a discharge led circuit but I just rely on my Digital Multimeter here it is at Amazon: amzn.to/2mDiPZF Thanks
Thanks for the reply. I was looking for more info on wattage requirement on the resistor, not the ohm resistance (drain time). I'm guessing a 1/2W resistor may burn out on an large HVAC capacitor. But a 50W will not. Maybe a better question is, how did you determine you needed a 5W resistor for this project?
You're most welcome. I'm glad and very happy to know that I could help you. Thank you so much for watching, commenting and the very kind words. I appreciate it greatly. All the best.👍😀
Hello Richard, Thanks for your design and time on this video. Question; by using the calculator link you recommended here, I notice that by decreasing the resistance value, the time to complete the discharge also decreases. so in your rig shown here it takes about 22 seconds using the 10k ohm resister to complete the discharge but switching to a 1K ohm cuts the discharge time to 3 seconds. Is there a reason to keep the discharge time long vs. getting it done in a few seconds?
The slower discharge is "allegedly" easier on the capacitor and less likely to create discharge sparks on connection. Also the slower discharge keeps the temperature on the whole circuit cooler. Thank you for watching and commenting. I appreciate it greatly. All the best.👍😀
kudos, excellent video followup based on your other video on discharging caps. The only thing I could think of adding would be a small switch box where you could dial in different discharge resistors based on capacitance and voltage charge.
Thanks. Good idea. You could use a potentiometer en.wikipedia.org/wiki/Potentiometer (variable resistor) to dial any resistance in a range too. Thanks for commenting and the feed back.
This newbie think you have a great discharge tool, Richard and how cool is that discharge calculator. Question: 1. Using your example but changing the number from 30 seconds to 5 seconds yields just over 0.34 volts left to discharge. Can one assume that while so low a voltage may be safe to handle there could be a risk to some devices if one were to accidentally discharge the balance into that delicate device, 2. A slower discharge will encourage at longer life for the cap, and 3. It occurred to me to solder some extra multimeter leads in place with this discharge tool to watch and verify discharge instead of waiting. What say you and would those lead be soldered in series or parallel? Thx!👍
How did you land on 12AWG wire? I'd assume you were interested in a specific resistance value (Ohms) Do you think 10 or 16AWG would work with these resistors/ this application?
Great video. Very detailed and easy to understand. I've made a discharge tool and bought the capacitor I need. Now I'm trying to figure out how to charge the Capacitor up to about 120 volts to use my discharge tool. How do I charge the Cap up for testing purposes ?
That is what I used in this video. See the link in the video description. Thank you for watching and commenting. I appreciate it greatly. All the best.
So I ordered the resistor, got alligator clips, soldered, and made a very, very nice probe, just to find out that the microwave cap has a built in resistor! I guess it';s good to have for working on computers or other.
That depends on whether the resistor is working or not. Also you don't know how long the resistor is designed to take to discharge the capacitor. Be safe. Thanks.
@@danielwarren129 It's moving from the negative to the positive. Imagine electricity in a capacitor or a battery as negatively electrons being separated from their paired positive charged counterpart. When you complete the circuit, it lets them flow to bind with the positive charge which neutralizes them.
A gun is always loaded, and a capacitor is always fully charged until you have checked for yourself that it isn't. You can always use a higher voltage rated capacitor, if it will physically fit. It should have the same capacitance rating. Some older circuits will specify capacitors of non-preferred values, in which case use the nearest preferred value, e.g. 22uF to replace a 25uF.
I would say no. Discharge it first and be safe. When you put the new fuse in it will close the circuit and you don't want to do that with a charge in the capacitor. Thanks and be safe.
Thank you so much for watching, commenting and the valuable feedback. I appreciate it greatly. Subscribe, Click The Bell and stay tuned! All the best.👍😀
You could try it but make sure that your meter can handle 440V + on the ohms check. I would not recommend it though. Thank you so much for commenting. I appreciate it greatly. All the best.👍😀
Just a little tidbit. Two of those springy and twangy doorstop/bumpers mounted to a heavy base (or magnets also) make a great pair of helping hands for holding wire and terminals for soldering. You just have to bend and slip the wire/terminal into a section of the tightly wound spring. A decent sized base also will retain solder dropping also.
Thank you for your skills and the video. I just made one with a 5/20 ceramic resistor. I did not have braided 12 AWG so I used a strand of house 12. I made it long enough to bend the ends close enough for capacitor terminals. getting ready to change out magnetron on microwave.
You are most welcome. I am glad I could help. Thanks for watching and commenting.
I now this is a while back ,but that is a great tutorial.Thats what I am going to build/use. Story coming up ! Way back about 1954 I was 9 .(UK) We just had our first TV. It always had problems, and the repair guy was at our house about every couple of weeks.He would always come in and discharge a large capacitor (as I now know),before working on the set.And He always used a screwdriver.Being interested in all things mechanical and electrical.I just asked him if there were a way that it could be done slower, instead of getting that large “CRACK” His reply was “Son, when you have worked on WW2 Radar.This is chicken feed, back in those days they were “real men’s capacitors.” My young thoughts were Wow! If this gives a crack! what must “they” have done? From then on I thought he was an electronics God.
Update: used my tool tonight on old capacitor and new one received in mail. Used DMM to determine both capacitors were good but installed new one due to it being more in spec. Thank you again for your knowledge on this potentially dangerous equipment.
Happy to hear of your success. You are again welcome. Thanks for the feedback and kind comments.
The man with the Zip ties i use hundreds of them, great video interesting, music slight distraction Thank you!
Zip ties the new and very improved duct tape. I don't use the music anymore unless I have a time lapsed segment then I use it as audio filler. Thank you for watching, commenting and the valuable feedback. I appreciate it greatly. All the best. 👍😀
richard, best video on this essential tool, thank you!
Just came back to a/c repair ( retired and got bored ) and love the video. Always liked dong things the right way.
You are most welcome. Thank you for watching and the kind words. All the best.
You can just use a lamp to discharge any capacitor under say 150v. Connect the plug of the lamp to the capacitor leads with wire and turn the lamp on. The lightbulb will provide the needed resistance.
I have never done this with a lamp so I can't really recommend it. I know what the resistance value is for my resistor but I can't guarantee the resistance of a random lamp. Thanks
a 60 watt lightbulb on a 120v power source means it runs with .5 amps based on ohms law. This means its resistance is 240 ohms. So it is a 240 ohm resistor rated for 60 watts. The lamp is not relevant here it is the bulb that is relevant. The prongs of the lamp are just the attachment interface making the discharge easier.
Cool. Thanks.
I need to get me one of those auto-adjusting wire stripper tools!
Very handy indeed! Thank you for watching and commenting. I appreciate it greatly. All the best.👍😀
Hello Richard, greetings from the Philippines, just finished watching this video, it is very informative, I have question, what I have right here is a 2W 39 Ohm ceramic resistor that I can get from a spare electric fan board, is this value of R can be used as a replacement. We are still on a lockdown we cannot go out and stores are still closed.. Looking forward..
Great video!!! Thank you for the design too.
You are most welcome. Thank you for watching, commenting and the kind words. All the best.
would it be even better to use a bigger resister. Also liked the background music.
It depends on your application but yes you could use a larger resistor. Thanks and all the best.
Great video...thx for posting. Couple questions 1) How do you calculate the resistor wattage rating needed to safely handle a given capacitor? 2) Can you put an LED in-line to verify the energy is draining/drained.
I aim for a 30 to 45 second discharge time as I know that will not harm
the capacitor. Here is the calculator I used
www.learningaboutelectronics.com/Articles/Capacitor-discharge-calculator.php#answer
as you can see the resistor value will vary as the value of the
capacitor changes. Play with the equation to see what best works for
you. You could build a discharge led circuit but I just rely on my
Digital Multimeter here it is at Amazon: amzn.to/2mDiPZF Thanks
Thanks for the reply. I was looking for more info on wattage requirement on the resistor, not the ohm resistance (drain time). I'm guessing a 1/2W resistor may burn out on an large HVAC capacitor. But a 50W will not. Maybe a better question is, how did you determine you needed a 5W resistor for this project?
Thx for the 10k info. Will use 50w for 1050v cap bank...
You're most welcome. I'm glad and very happy to know that I could help you. Thank you so much for watching, commenting and the very kind words. I appreciate it greatly. All the best.👍😀
Thanks for the thoughts you have provided here.
You are most welcome. Thanks for watching and the kind comment.
Hello Richard, Thanks for your design and time on this video.
Question; by using the calculator link you recommended here, I notice that by decreasing the resistance value, the time to complete the discharge also decreases. so in your rig shown here it takes about 22 seconds using the 10k ohm resister to complete the discharge but switching to a 1K ohm cuts the discharge time to 3 seconds. Is there a reason to keep the discharge time long vs. getting it done in a few seconds?
The slower discharge is "allegedly" easier on the capacitor and less likely to create discharge sparks on connection. Also the slower discharge keeps the temperature on the whole circuit cooler. Thank you for watching and commenting. I appreciate it greatly. All the best.👍😀
kudos, excellent video followup based on your other video on discharging caps. The only thing I could think of adding would be a small switch box where you could dial in different discharge resistors based on capacitance and voltage charge.
Thanks. Good idea. You could use a potentiometer en.wikipedia.org/wiki/Potentiometer (variable resistor) to dial any resistance in a range too. Thanks for commenting and the feed back.
Appreciate all the work and explainations. Cheers buddy
This newbie think you have a great discharge tool, Richard and how cool is that discharge calculator.
Question: 1. Using your example but changing the number from 30 seconds to 5 seconds yields just over 0.34 volts left to discharge. Can one assume that while so low a voltage may be safe to handle there could be a risk to some devices if one were to accidentally discharge the balance into that delicate device, 2. A slower discharge will encourage at longer life for the cap, and 3. It occurred to me to solder some extra multimeter leads in place with this discharge tool to watch and verify discharge instead of waiting. What say you and would those lead be soldered in series or parallel?
Thx!👍
Nice video! If you don’t want to pay $7 for the Supco capacitor discharge pen this is a great alternative.
How did you land on 12AWG wire? I'd assume you were interested in a specific resistance value (Ohms) Do you think 10 or 16AWG would work with these resistors/ this application?
It's plenty thick for the application but you can go with heavier if you wish. Thanks.
Great video. Very detailed and easy to understand. I've made a discharge tool and bought the capacitor I need. Now I'm trying to figure out how to charge the Capacitor up to about 120 volts to use my discharge tool. How do I charge the Cap up for testing purposes ?
AIN'T IT JUST AIN'T IT 😜 lols
Thanks for this video. Is there any problem if I discharge a capacitor by doing short circuit?
There is a possibility that you will cause damage to the capacitor. Thanks.
Thanks for this video. clear and Nicely explained.
is it possible to use 5W Watt 10K Ohm?
That is what I used in this video. See the link in the video description. Thank you for watching and commenting. I appreciate it greatly. All the best.
So I ordered the resistor, got alligator clips, soldered, and made a very, very nice probe, just to find out that the microwave cap has a built in resistor! I guess it';s good to have for working on computers or other.
Thanks.
girohead So if the microwave cap has a built in resistor, you don't need this contraption or do you?
That depends on whether the resistor is working or not. Also you don't know how long the resistor is designed to take to discharge the capacitor. Be safe. Thanks.
Thanks for the info on this D.i.Y. discharge tool. Microwave caps are rated to some 2100v. Will your resister of 5w 10kw still be adequate.
Microwave caps are up to 5000v
Daniel Warren , ok so is that a yes or no?
very nice mr Lloyd ......awesome demonstration....you are now my idol.....anyway Sir how to charge the dischaged capacitor?
Nicely explained. Good tool! Thanks!
You are most welcome. Thanks for watching and the kind words. All the best.
How would you use this on a microwave capacitor which has two terminals
Will the resistor wear out in time? Thanks
I can't see why it would other than being physically damaged it should last a lifetime. Thanks.
@@richardlloydusa Where does the electricity go to when the tool is draining it?? Where's it draining to?
@@danielwarren129 It's moving from the negative to the positive. Imagine electricity in a capacitor or a battery as negatively electrons being separated from their paired positive charged counterpart. When you complete the circuit, it lets them flow to bind with the positive charge which neutralizes them.
@@danielwarren129 The energy becomes heat within the resistor and dissipates into the environment.
Awesome. Great demo of the discharge. Thanks again.
I have a bad capacitor will it discharge on its own? And could I use a higher volt capacitor in place of the lower one?
It may or it may not. It's best to treat it as a charged capacitor regardless. I recommend using the manufacturer specified capacitor. Thanks.
not a higher volt, but a higher microfarad rating is ok
A gun is always loaded, and a capacitor is always fully charged until you have checked for yourself that it isn't. You can always use a higher voltage rated capacitor, if it will physically fit. It should have the same capacitance rating. Some older circuits will specify capacitors of non-preferred values, in which case use the nearest preferred value, e.g. 22uF to replace a 25uF.
explained very well, thank you
You are welcome. Thanks for watching and the kind comment.
thank you
Thanks
You are most welcome. Thank you for watching, commenting and the kind words. I appreciate it greatly. All the best.
hey just wondering is it safe to replace the fuse without discharging the capacitor in a microwave?
I would say no. Discharge it first and be safe. When you put the new fuse in it will close the circuit and you don't want to do that with a charge in the capacitor. Thanks and be safe.
Richard Lloyd
will it discharge on its own over time?
Again I would not count on it discharging on it's own. Be safe and discharge it properly. Thanks.
Wow this is great!
Thank you very much.
Well done thank you
Anyone ever tell you that you sound a little like Norm Macdonald? Lol great job nice to know
Yes, I have heard that he sounds like ME. Thank you so much for commenting. I appreciate it greatly. All the best.👍😀
1/4 inch is closer to 6mm
Thank you so much for watching, commenting and the valuable feedback. I appreciate it greatly. Subscribe, Click The Bell and stay tuned! All the best.👍😀
Ola' - why not use ohms section of the multimeter to discharge a capacitor,? ;:-_4;:
You could try it but make sure that your meter can handle 440V + on the ohms check. I would not recommend it though. Thank you so much for commenting. I appreciate it greatly. All the best.👍😀
Actually actually actual actually
THANK YOU FOR SCHOOL
I just use a knife although it ends up scaring me
would a resistor and a pair of needle nose pliers constitute a poor man's version of said Capacitor Discharge Tool [ahem] Lite? ha ha
My comment would be, "Be safe." Thank you so much for commenting and the very kind words. I appreciate it greatly. All the best.👍😀
Solder It's Solder not sodder!! lol