- momentary pushbutton switch - 1 Update
- Basic fuse question - 8 Updates
- intercom circuit - 1 Update
| "humbled valiant" <nobody@nowhere.com>: Jan 29 11:42AM -0500 I am looking for a push button switch that turns on when it is pressed down, stays on while it stays depressed and turns off when it is released. I am running into "momentary pushbutton" switches such as this candidate: http://www.allelectronics.com/make-a-store/item/pb-211/red-jumbo-pushbutton-switch/1.html Do switches like this meet my qualifications? |
| dave@daveryder.com: Jan 28 11:40PM -0800 On Thursday, October 17, 2013 at 8:29:15 PM UTC-5, Phil Allison wrote: > ** Got any idea what the letter "T" stands for ? > Hint - it ain't "time". > ... Phil Hey, I know there is some joking around going on here (and some animosity, too apparently) but the "T" DOES actually stand for: "T = Time. Time Delay or Slow Blow.(Typically open between 100 and 300 ms @ ten times the rated current)" Correct? Or am I missing something? BTW that comes from this google cached page: http://webcache.googleusercontent.com/search?q=cache:E3algcJXUCMJ:highfields-arc.co.uk/constructors/info/fusecolours.htm+&cd=2&hl=en&ct=clnk&gl=us I'm just trying to learn, I've got to replace that same damn fuse, and I'm frankly having a bitch of a time figuring out what's causing it to blow (it's the psu from a 32' flatscreen tv if that matters) Replaced a bunch of bad caps, and it powers up for about 3 seconds with a nice picture, and then bam blown fuse. Does rogaine help for hair regrowth that you pulled out yourself lol? |
| dave@daveryder.com: Jan 28 11:46PM -0800 > Correct? Or am I missing something? BTW that comes from this google cached page: > http://webcache.googleusercontent.com/search?q=cache:E3algcJXUCMJ:highfields-arc.co.uk/constructors/info/fusecolours.htm+&cd=2&hl=en&ct=clnk&gl=us > I'm just trying to learn, I've got to replace that same damn fuse, and I'm frankly having a bitch of a time figuring out what's causing it to blow (it's the psu from a 32' flatscreen tv if that matters) Replaced a bunch of bad caps, and it powers up for about 3 seconds with a nice picture, and then bam blown fuse. Does rogaine help for hair regrowth that you pulled out yourself lol? Oh and another thing that has me curious is the fuse was wrapped in rubber shrinkwrap, even though it wasn't anywhere near anything metallic that could short it out, any ideas why? |
| Mike <news@mjcoon.plus.com>: Jan 29 02:43AM -0600 On Wed, 28 Jan 2015 23:46:26 -0800, dave wrote: > Oh and another thing that has me curious is the fuse was wrapped in > rubber shrinkwrap, even though it wasn't anywhere near anything metallic > that could short it out, any ideas why? That's easier to guess: to protect anyone who happens to be looking at the fuse when it blows and the glass casing shatters? Mike. |
| Phil Allison <pallison49@gmail.com>: Jan 29 01:16AM -0800 > > Hint - it ain't "time". > Hey, I know there is some joking around going on here (and some animosity, too apparently) but the "T" DOES actually stand for: "T = Time. Time Delay or Slow Blow.(Typically open between 100 and 300 ms @ ten times the rated current)" > Correct? Or am I missing something? ** Yes - the word with that T as the initial letter. It's the German word "Trage" meaning "dragged out" or leaden. All the letter codes on common fuses are for German words. F = " Flink " for quickly or rapid. http://www.thefusewarehouse.com/pages/learn_fuse_markings.php Amaze your friends... ... Phil |
| mike <ham789@netzero.net>: Jan 29 03:39AM -0800 > Correct? Or am I missing something? BTW that comes from this google cached page: > http://webcache.googleusercontent.com/search?q=cache:E3algcJXUCMJ:highfields-arc.co.uk/constructors/info/fusecolours.htm+&cd=2&hl=en&ct=clnk&gl=us > I'm just trying to learn, I've got to replace that same damn fuse, and I'm frankly having a bitch of a time figuring out what's causing it to blow (it's the psu from a 32' flatscreen tv if that matters) Replaced a bunch of bad caps, and it powers up for about 3 seconds with a nice picture, and then bam blown fuse. Does rogaine help for hair regrowth that you pulled out yourself lol? Here's the dark side of replacing caps. Switching power supplies often work by stuffing pulses of current thru inductors into caps from a higher voltage. Primary failure mode of caps is increased series resistance, ESR. When that resistance increases, there's a step in voltage across the cap when the current is being stuffed in. The regulator is looking at average voltage, so it reduces the output voltage slightly to make the average voltage, including that step, to be the desired output. Over time, that step gets bigger and bigger. You don't see any symptoms until the step gets big enough to disrupt the circuit. By the time the system shuts down, damage may have been done. Had one monitor where the system processor had been fried by the peak voltage. Had 19V spikes on a 5V supply. In another, there were totem-pole fets driving the transformer for the backlight. One of them had been damaged and had high leakage. The backlight came up and ran for a few seconds until the other fet overheated and blew the fuse. That's why it's often a good idea to change all the caps at once. If you're lucky, and most are, you caught it before permanent damage was done. So, back to your problem... Most any fuse of the correct current rating should work for more than three seconds. Yes, the right fuse is best, but fix the circuit first. |
| Allodoxaphobia <knock_yourself_out@example.net>: Jan 29 01:37PM > ... (it's the psu from a 32' flatscreen tv if that matters) Wow! Are you operating a small drive-in multi-media center? :-) |
| John Robertson <spam@flippers.com>: Jan 29 07:44AM -0800 On 01/29/2015 1:16 AM, Phil Allison wrote: > Amaze your friends... > .... Phil Isn't that chart just for the European fuses? It is interesting none the less... John :-#)# -- (Please post followups or tech inquiries to the newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
| dave@daveryder.com: Jan 29 08:42AM -0800 On Thursday, January 29, 2015 at 9:44:57 AM UTC-6, John Robertson wrote: > (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) > www.flippers.com > "Old pinballers never die, they just flip out." Thanks everyone for being so helpful, it's always cool to pick the brains of some guys who know what they're doing :) ps about the shrink wrap, it's not a glass fuse, it's a ceramic fuse so the wrapping is still sort of a mystery I guess. Anyway thanks again I'll keep plugging away at it til I figure it out Dave |
| "humbled valiant" <nobody@nowhere.com>: Jan 28 03:49PM -0500 http://www.stonetabernacle.com/INTERCOM_CIRCUIT.html is my intercom/telephone/sounder/strobe circuit between shop and garage. It utilizes an assembled part (P1) on the schematic, http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2151671_-1 The shop has machinery that needs a loud bell and a strobe when the phone rings. It also needs these to get attention for intercom paging. This is needed from the house to the shop and from the shop to the house. I haven't built the thing yet. All the materials are expensive. Notice that the intercom is made up of 2 wired phones with one of the phone wires cut and a 9v battery and 200 ohm resistor inserted in series with it. This makes for a cheap intercom but it also needs an alarm to alert the other end that it needs to talk. |
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