sci.electronics.repair@googlegroups.com

Google Groups

Mike S <mscir@yahoo.com>: Nov 02 07:46PM -0800 My Dewalt Drill trigger is failing, sometimes I have to hold it on for 30 seconds or more while I disconnect and reconnect the battery, move the fwd/rev swtich around, spin the drill chuck, hit the drill with my palm shake it... it comes on when it feels like it. I haven't correlated it to moon phases, yet. I found a part on ebay for $63 so I think I'll try fixing it first, otherwise it's a new drill purchase instead extending the life of this old beast.   This is the assembly https://i.imgur.com/LKoThQf.jpg   It looks similar to this https://www.amazon.com/Black-Decker-152274-19SV-Switch-V-S-R/dp/B00BFDL6DQ/ref=sr_1_6   Has anyone taken one of these apart? Does anyone have any idea how these are constructed? it looks like a sizeable heat sink so I'm guessing it's a wire-wound pot.   TIA, Mike

Phil Allison <pallison49@gmail.com>: Nov 02 09:31PM -0800 Mike S wrote:   -------------   > Has anyone taken one of these apart? Does anyone have any idea how these > are constructed? it looks like a sizeable heat sink so I'm guessing it's > a wire-wound pot.   ** Not at all likely, almost certain to be a Mosfet drive using PWM.   Does it not make a whistling sound when you pull the trigger in slightly?     .... Phil

Jeff Liebermann <jeffl@cruzio.com>: Nov 02 10:14PM -0800 >My Dewalt Drill trigger is failing...   Does the drill have a model number? Is there a number on the switch assembly? <https://www.ereplacementparts.com/dewalt-cordless-drill-parts-c-1009_1162.html>     -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

T i m <news@spaced.me.uk>: Nov 03 11:49AM >the fwd/rev swtich around, spin the drill chuck, hit the drill with my >palm shake it... it comes on when it feels like it. I haven't correlated >it to moon phases, yet.   ;-)   Could it be the brushes if there is no direct correlation to doing / moving anything?   Cheers, T i m

amdx <amdx@knology.net>: Nov 03 06:35AM -0600 On 11/2/2020 9:46 PM, Mike S wrote: > guessing it's a wire-wound pot.   > TIA, > Mike   I've had a few battery powered Dewalt drills. I won't get a Dewalt drill again. I 'm disappointed in the battery lifetime*, I've had chuck problems, also the clips that hold the battery in fail and the battery must be pushed back in. I'm not sure what I will get, but I know what I won't get.    *life of battery not discharge time.     -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

RD <randy.day@sasktel.netx>: Nov 03 07:50AM -0600 In article <rnqjqr$fm9$1@dont-email.me>, mscir@yahoo.com says...   > My Dewalt Drill trigger is failing, sometimes I have to hold it on for > 30 seconds or more while I disconnect and reconnect the battery, move   We had a couple Dewalts at work with the same issue; after a bit of searching online, the fix was dirt buildup had dislodged a retaining clip on the fwd/rev selector.   Can't remember the site (sorry), but it should be searchable. Disassemble the f/r assembly, clean and reassemble.   HTH

Fox's Mercantile <jdangus@att.net>: Nov 03 09:28AM -0600 On 11/3/20 6:35 AM, amdx wrote: > I'm not sure what I will get, but I know what I won't get.   Makita.   -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

John-Del <ohger1s@gmail.com>: Nov 02 09:20AM -0800 On Sunday, November 1, 2020 at 3:03:38 PM UTC-5, Fox's Mercantile wrote: > On 11/1/20 11:25 AM, Edward Hernandez wrote: > > Hey! Look at the pony boy being helpful!   > Piss off charger boy.   LOL. "charger boy"..

"Edward H." <dtgamer99@gmail.com>: Nov 03 06:11AM -0800 > > > Hey! Look at the pony boy being helpful!   > > Piss off charger boy.   > LOL. "charger boy"..   I know! If he isn't cursing this is the best he can do. lol. Silly 41usenet.

ABLE1 <somewhere@nowhere.net>: Nov 02 02:02PM -0500 On 11/2/2020 10:39 AM, legg wrote:   > A PTC fuse won't do the same job - they require more info than > you have to apply reliably.   > RL   Ok??   RL,   What additional information would I need "to buy the right one"??   120VAC .125 amps fast acting a good one shows 5.9 ohms while installed on board – 55 deg C to 90 deg C.   So maybe this one??   https://www.littelfuse.com/~/media/electronics/datasheets/resettable_ptcs/littelfuse_ptc_lvr_datasheet.pdf.pdf   The LVR025S to be specific.   BTW this is more of an experiment or some personal edification.   As is said; Need to learn something new ever day.   Thanks for any input. (Quality input that is)   Les

Fox's Mercantile <jdangus@att.net>: Nov 02 01:13PM -0600 On 11/2/20 9:20 AM, Edward H. wrote: > Look at such a great effort all for me!   Oh look, monkey boy figured out how to change his name.   -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

Jeff Liebermann <jeffl@cruzio.com>: Nov 02 11:39AM -0800 On Sun, 1 Nov 2020 22:49:59 -0500, ABLE1 <somewhere@nowhere.net> wrote:     >If I would replace or jumper the B = RXEF010 resetable fuse the board >would work, meet code, and almost never have to concern myself with >it in the future??   No. I would replace it with as close to the original SMD fuse as possible. In an emergency, I might replace the tiny SMD fuse with a much larger fuse with wire leads. If doing development work on a prototype, I would probably install a rather expensive socket and rectangular fuse. However, for consumer use, it will always be the original fuse.   The reason is that I don't know anything about the device that you own. Most important, I don't know what it will do if a low AC voltage is applied to the device. That's what will happen with a PTC resettable fuse. The circuit does not go to completely open when the PTC fuse is tripped. It goes to a fairly high resistance, and then only as long as the fuse remains hot. To keep it hot, there has to be a high current going through the fuse. That means there's power applied to the rest of the PC board while the fuse is tripped. If you look at the specs, that's the "hold current". Done correctly, that will keep the fuse warm, and the power MOSTLY removed from the rest of the circuit. Done wrong, it is possible that the fuse will cause the device to cycle on and off repeatedly as the PTC fuse cycles through hot and cold cycles. There are places and devices where a resettable fuse is appropriate and safe. However, since I have no idea what you're working with, I can't predict what will happen if you cram in a PPTC resettable fuse and certainly don't want to take the risk suggesting you do something that might be unsafe.   Also, is this really a problem that is worth solving? I doubt it. Put in the correct fuse and you won't have to worry about the device burning your house down.   Incidentally, I once repaired a small 13.6V 30A switching power supply, which had a PPTC resettable fuse in the AC line. The problem was obvious as there was a hole burned into the PCB where the PTC resettable fuse had been. I could find no part number or specs on the fuse making replacement difficult. I soon discovered why they used a resettable fuse. It wasn't for convenience or size. It was because the inrush current on this power supply was so high, that even a slow-blo fuse would blow up if switched on with a 15A load. The designer decided to use the PPTC fuse as an inrush current limiter, which is a really bad idea. At some point along the load curve and near maximum current, the operating point landed on the transition line between low and high resistance. Since there was no hysteresis in the transition line, the maximum power dissipation point for the PPTC fuse was also somewhere along the curve. As bad luck would have it, the customer's was operating almost on the same point of the curve, causing the PTC fuse to become very hot. After a few days of this kind of abuse, it burned a hole in the PCB and carbonized the PTC fuse.   I made a few measurements and calculations and found a higher current replacement PTC fuse. That brought the PTC fuse transition line to somewhat higher than the maximum current. That fixed one problem and created a new problem. The PTC would never trip because the over-current protection in the power supply would turn down the power supply before the PTC fuse was able to do the same. However, the over-current protection was set to begin at about 10A above the maximum output current and had no hysteresis. So, this mess is going to require some redesign. I changed a few parts to bring the over-current threshold to the maximum rated current and enabled hysteresis by installing a resistor that the designer forgot. I replaced the PTC fuse with a Slo-Blo conventional fuse, and inserted a PTC thermistor inrush current limiter intended only to prevent blowing the fuse under normal operation. Problem solved and it's been working just fine for about 3 years.   Are you prepared to do something similar with your "circuit board"?   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

"Edward H." <dtgamer99@gmail.com>: Nov 02 11:51AM -0800 On Monday, November 2, 2020 at 1:13:44 PM UTC-6, soft-stool Fox Comics queefed:   > Oh look, monkey boy figured out how to change his name.   I'm learning a lot everyday old fella. Like how much smaller you've become since I first ran into you. Here I thought, "41 yrs on usenet! Wowee!" Ahhaha. You continue to shrink and your posts seem so much softer.

ABLE1 <somewhere@nowhere.net>: Nov 02 03:51PM -0500 On 11/2/2020 2:39 PM, Jeff Liebermann wrote: > the fuse under normal operation. Problem solved and it's been working > just fine for about 3 years.   > Are you prepared to do something similar with your "circuit board"?   Jeff,   Actually no I am not. This is for a wall clock timer controlled correcting board. Basically upon a signal from the master clock the clock then adjusts to the right time.     I was thinking of trying a retro fix of board to see if it would work. I realized early on that I would probably not do this, but, I wanted to get opinions on the plus and minus of choices.   Since you put the possible issues the way you did I will totally scratch that idea and move on to other stuff. However, I doubt there would be any major issues at the current draw max of .5 amps. The clock would just stop running!!   Thanks for the detailed typing. All very helpful and informative to my brain antique brain. Learning new stuff is always beneficial.   Thanks again and have a good week.   Les

Fox's Mercantile <jdangus@att.net>: Nov 02 01:15PM -0600 On 11/2/20 9:19 AM, Edward H. wrote: > Why do you keep creating fake names?   You're delusional. I have never used a fake name.     -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

"Edward H." <dtgamer99@gmail.com>: Nov 02 11:47AM -0800 On Monday, November 2, 2020 at 1:15:45 PM UTC-6, Enema man Fox Comics queeffed:   > You're delusional. I have never used a fake name.   Let's see what the comic man is up to. You're responding to my posts. Good work. Keep going.

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.