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Hello ,I have build NPN which base is being biased with a current source ,the problem that My collector current is very low no matter the current i put in the base as shown in the photo and simulation. Why i cant see the Ic/Ib=beta ratio? Thanks. /g/electronics101/files/john233/npn_circuit.zip

I believe it is true that some neon bulbs have a tiny amount of radioactive material inside to improve (lower) the firing voltage. I read or heard that from a number of sources. But I can't help you with the NE-1. I never came across it myself. Andy

Hi there, again, Further to my query of a flashing LED circuit not working. From all the comments I've had, it seems as though it is a "dud" circuit, consequently I have gone to the "Plan B" circuit which I discovered when I was searching for a simple flashing circuit. This uses an NE555 timer IC. I will attach the circuit shortly in the files section. To summarise it has the 555 timer, 3 resistors - 100K ohms, 270K ohms, & 470K ohms, 1 capacitor - 1uF, and of course the Red 5mm LED. The circuit uses a 5-12VDC supply. Can I use an electrolytic 63V, 1uF or another type such as a Tantalum or a 100v Non-polarised type. FWIW, I'm putting a navigation type flashing light on top of a building I'm making for my model RR layout. Thanks, Ian

555 timers also are not subject to voltage. Anything from 5 to 16 volts will give exactly the same timing because they work on deviding the supply by 3 using 3 5K resistors, hence the name 555 and switch at 1/3 and 2/3

Hi all,is it possible to attatch a file here?,i am struggling trying to make a pcb for toner transfer using eagle and need to upload the schematic+ board files but cant see how i can do that, Is it possible?.thanks all.

i am trying to make a schematic that has an arduino nano at the heart of it,the footprint of the nano v3 in the schematic editor seems to have missing pins and some in the wrong place,any ideas?,i am trying to use kicad ver 8.

The following items have been added to the Files area of the [email protected] group. /Flashing LED circuit_2_PCB layout.jpg By: Ian Bell <genealogyinfo@...> Description: Further to my query of a flashing LED circuit not working. (PCB solder side layout)

Ian Bell <genealogyinfo@...> added folder /Further to my query of a flashing LED circuit not working Description: Circuit for "Further to my query of a flashing LED circuit not working" The following items have been added to the Files area of the [email protected] group. /Flashing LED circuit_2.jpg By: Ian Bell <genealogyinfo@...> Description: Further to my query of a flashing LED circuit not working

I recall my mother complaining that she felt a "tingle" when touching the stainless steel edge on her Formica counter top while opening the refrigerator. I was probably 10 at the time but I knew enough to run a ground from the BX cable to the counter edge. It was probably some leakage in the fridge compressor but it took a while for her to convince my father there was something wrong. This was in the early 50's so there were no polarized plugs. Dan Kahn On Tuesday, November 12, 2024 at 12:07:25 PM EST, wn4isx via groups.io <wn4isx@...> wrote: I guess it's time to bring up "The All American Five" and AC/DC operation. Parts of Detroit were 110V DC up until sometime in the 1960s. An aunt lived there and told me of the woes of getting a TV that worked. AC/DC radios most often had one side of the AC mains wired to the chassis. Which gave you a 50/50 chance of a hot chassis given non-polarized 2 conductor power plugs. Later units "isolated" the chassis with a capacitor, still deadly. The outer case and knobs were designed to prevent contact with the chassis. My younger sister pulled Mom's radio off the table, shattered the case. I was told the throw the radio away, saved it, plugged in and it worked. I was 7 and touched the case. Our garage had a dirt floor and I was barefooted and got the urine knocked out of me. My father demonstrated the danger with a light bulb. That lesson stayed with me. So if you are restoring an All American Five (no idea why anyone would the performance was amazingly mediocre) be aware the chassis might be hot. Oh, the insulation in pre ?1970 Singer sewing machines was marginal and the case could easily be hot. My older sister was shocked on Mom's Singer. And, lights are supposed the have the shell wired to neutral. Even with polarized 2 conductor mains connectors, do not trust the wiring!!!! Been bit once really good because I assumed "surely they wired it properly at the factory." Nope. shell was hot, switch was in the neutral. Trust but verify applies to electronics as well as international weapons treaties.

hi, I would like to understand how the various PowerBank work for mobile phones .... Let me explain better, I wanted to feed a classic flashing light with The usual timer with IC 555 and an LED diode, all work with 5 volt. Except that I connected it to the 4 different powerbank that I have but nothing, off !!! With the tester in fact I read from 2 to 3 volts out of the way .... If, however, the various keyboards, a miracle, the 5 volt and the circuit comes out Outside it works! Only then after a while ... everything goes out and the 5 volts still disappear. So there must be something to do on the connector for I think make Powerbank understand that there is an external load and to continue To give the 5 volts out of the way, right? But how should I do, maybe some resistance or ... but where? help .... who knows more? Thank you 73

Hi all , I have a project that uses an arduino nano , I have not yet mastered pcb design , I am after a jped to scale if poss of a nano footprint pic,for a sort of pin brakeout so i can toner transfer that to a pcb then do the rest of the artwork by hand if that makes sense ?,also the same for a tactile switch as well,can anyone help,?,a png or jpeg is ok,cheers Paul.

Your comments remind me of using the avalanche mode to drive MHz ultrasonic transducers over 40 years ago. The DC supply was about 300 V and the pulses in the ns range. I controlled the base voltage to keep the transistor from avalanching and pulsed the base to trigger the breakdown. I got to look up the details. Bertho From: [email protected] <[email protected]> On Behalf Of wn4isx From my days in EE class (1973~1979) Motorola and RCA referred to avalanche mode as "breakdown that collapses to (near) zero." Much like a 4 layer Shockly diode. A zener or normal BE/BC breakdown stabilizes at the breakdown voltage, where "avalanche" (as used by Motorola way back when) refers to a switch like action. The 7nS pulse generator I gave a link to uses a transistor in what I was taught was avalanche mode. The 90V charges a capacitor through a resistor, at some voltage the C/E junctions avalanche and produce an unholy narrow pulse. I built the circuit using a NE555 driving a complimentary pair driving an 8 ohm to 1K followed by a voltage quad or quint (5) multplier. The transistor type, and I think (if I remember correctly) manufacturer were important. I know not all Motorolas worked, most did and I think no RCA worked.

Check this out: https://www.youtube.com/watch?v=jH2a6CeTFoU Now I'm gonna have to check my clip leads... Bought a couple of rolls of small wire at a dollar store a while back, they are definitely reacting to a magnet as well. Oh well, for a dollar I'm not complaining, and they're usable to some small extent. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

If I'm not mistaken, these days CdS photocells may be hard to come by. They are toxic (HIGHLY toxic, I am told) and I think have been banned for a while now in most parts of the world. Bummer. Andy

As a technology, the conversion of a C program to Verilog is twenty or thirty years old. Still, it was new to me and I had a great time figuring it out. :) A write up of the C-to-Verilog process is here: https://spreadsheetstatemachines.org/index.php?/pages/singleassignment.html It is an easy read so you might want to start at the beginning: https://spreadsheetstatemachines.org/ The next step is to select a spreadsheet to modify to make it into a parallel programming language. thanks Bob Smith

wn4isx wrote: Note, by the way, he is talking about a Shockley diode -- NOT a Schottky diode. They are rather different beasts, named for different physicists. I never ran into a Shockley diode before, but I heard of them. I had much more hands-on use with Schottky diodes. OTOH, I often refer to the Ideal Diode Law or Equation which is also known as the Shockley Diode Law. Mr. Shockley is credited as being one of the three inventors of the (bipolar) transistor at Bell Labs. Andy

Hi there, I have a circuit for an LED Flasher unit. I have reworked it about 3 times, but it still won't work. Could someone advise me whether it's the circuit itself is faulty or there another reason why I can't get it to work. It's been awhile since I've posted on here, so I may have trouble attaching the circuit. If the attachment doesn't show, could someone refresh my memory on how to add. I think I have to attach through Files, so here goes. Ian

Good instructables. Some members here could REALLY use this… Thanks Nuno T.

The following items have been added to the Files area of the [email protected] group. /LED Flasher.jpg By: Ian Bell <genealogyinfo@...> Description: LED Flasher circuit why won't it work

I've seen all sorts of specialized chips, or piles of discrete components used to get optimal drive for MOSFETs, but happened to stumble across this video: https://www.youtube.com/watch?v=FKqkRDM0Al0 It's a neat idea, and seems to work well. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin