R5, Bolt Action Carbine

Hey guys! After the "rebuff" I received from ZakS and FlyingFish10 (and more kind comments from TheDunkis and Raz1r Knex Bull3t) about how my K'NEX Gun: Declaration (R2) looked just like a ZKAR (to which I disagreed), I decided to rebuild and heavily edit my K'NEX gun Declaration (R2), changing the body and mechanisms so heavily that the comparison between it and the ZKAR would be virtually non-existent. After about three days of hard work, I have finally come up with this gun, the R5. With a brand new trigger mechanism and bullet transfer system, this gun is ENTIRELY different from any other bolt action gun you will find. While the bolt itself is heavily similar to the ZKAR / Zaktangle, almost everything else is entirely unrecognizable (except the magazine, that's a pretty standard yellow rod magazine). Features: Brand new trigger mechanism Brand new bullet transfer system Heavily edited (and improved) pin guide setup Comfortable stock Very reliable New magazine setup, with magazine breach Comfortable grip Flip-up back sight Great range: 50 - 70 ft. Preloadable magazine Internal magazine pusher 12 rd. magazine (could be increased) This version is by no means finished, but when I do finish it, I'll be sure to post a full set of instructions. Check out the image notes for more info. Tell me what you guys think I should change or add to this gun. I'd love to hear your comments. Quick Tip: When you have a magazine that is full of rounds try and make the last round different in some way, so that when you shoot the gun you know when the magazine is empty. This will prevent you from shooting the magazine pusher, and make it so that you don't have to keep track of how many rounds you've shot. -The Red Book of Westmarch

Posted by The Red Book of Westmarch 4 years ago


opamp voltage bias question.? Answered

Hello. i have a question about voltage bias.In some schematic of opamp use single power source , they use R1=R2 to make voltage bias (please see the example bellow) . But the value of R1 and R2 in other schematic i found are diffirent (R1=R2=100k or R1=R2=47k ,.... etc) How did they effect the circuit ? Thanks for advance ! sorry for my bad English .

Asked by login721 6 years ago


Dropping out of TGKTR3

As the title suggest, I am dropping out of the tournament. There are several reasons why.1. People don't like the founder of the contest being in it.2. I want to judge this last round personally so people probably won't like me judging my own entry.3. I already started taking apart my unfinished entry.For all those wondering, this was going to be my entry: http://www.youtube.com/watch?v=a6ekJEyP_FE

Posted by jollex 9 years ago


how do I connect the Wemos D1 r2 to an L298n motor driver to control 2 DC mootors?

Hi , I'm new and I'm looking for help to see how we can wire a Wemos d1 r2 and L298n motor driver. My objective is to control 2 DC motors with Blynk. I will really appreciate anyone's answer or sketch or link to help me out. thanks

Asked by huguens 1 year ago



TDA2003 opamp question? Answered

Hello i have some questions about the opamp TDA2003. 1.In the picture bellow the R1 and R2 make the gain for opamp .Gain=R2/R3=220/2.2=100. It's of if i replace the R2 with 2k resistor and R3 with 200 Ohms resistor ??? The gain still the same but i dont know if it still ok ?? 2.What the  C2(470uF) do in this schematic, what will happend if i replace it with a 100uF capacitor ? Thanks for advance! sorry for my bad English !

Asked by login721 6 years ago


TGKTR3

Round 3Last round.RulesMake a ball machine.Deadline: June 1st

Posted by jollex 9 years ago


decoder ?

Hello , I  am going to make  decoder  for micro controller ,   I want to know how does decoder make for  microcontroller I have 4 registers I =Instruction Register A= Address register R1= register R1 R2 =register R2 Logic 0= deactivate Logic 1= activate I     A   R1    R2        out 1   1    1         0            1     //  mov R1 1   1    0          1           1     // mov R2 I AR1R2        out 0000                 0000000000000001 0001                 0000000000000010 0010              0000000000000100 0011              0000000000001000 0100             0000000000010000 0101             0000000000100000  0110             0000000001000000  0111            0000000010000000  1000            0000000100000000   1001             0000001000000000 1010             0000010000000000 1011            0000100000000000 1100            0001000000000000 1101            0010000000000000 1110            0100000000000000 1111           1000000000000000 If I know input than how to know what will decode ?

Asked by vead 3 years ago


8 bit Instruction set ?

Hello experts I need some help I want to make 8 bit instruction using folloing component so I made one simple example 8 bit instruction set 4 bit opcode + 2 bit source register +2 bit destination register+ 4 bit data accumulator A memory register R1 memory register R2 memory register R3 opcode         source       destination       data 0010               00               00                 xx                  R1  01           A  01                xx                  R2  10               XX                xx                  R3  00               XX                xx load data directly into R1 mov R1#data opcode     source      destination       data 0010         R1 01          00                  data load data directly into R2 mov R2#data opcode     source      destination       data 0010         R2 10          00                  data load data directly into R3 mov R3#data opcode     source      destination       data 0010         R3 11          00                  data load data directly into A mov A#data opcode     source      destination       data 0010            00         A  01                  data mov the content of R1 into Accumulator mov A, R1 opcode     source      destination       data 0010         R1 01          01                  disable mov the content of R2 into Accumulator mov A, R2 opcode     source      destination       data 0010         R2 10          01                  disable mov the content of R3 into Accumulator mov A, R3 opcode     source      destination       data 0010         R3 11          01                 disable don't use any register disable opcode       source       destination       data 0010               00               00                 xx      don't use register

Asked by vead 3 years ago



Question about op amp frequency response? Answered

Hello , i have some question about op amp frequency response. i use non inverting like the scematic below.If i set  R1=10kΩ  , C1=220nF  ,  R2=100Ω  , C2=1uF . R1 and C1 will set low frequency response of opamp at 72Hz . R2 and C2 will set high frequency response of opamp at 1592Hz.  But how much it affect the signal in dB ? and how its affect the signal if i set R2=100k ,C2=1n (gain~11)? Can you give me the formula please ? Thanks very much! Sorry for my bad English!

Asked by login721 5 years ago



how to install arduino on windows 8.1?

I tired to install arduino 1.0.5 r2 on my pc but the serial port is greyed out what should i do ?  

Asked by Pranavthegreat 4 years ago



resistor id?

This might sound stupid, but being brand new to electronics i need to pose this question, i found a scematic with 3 resistors on, 1 is a variable rated as R1 100K, the second R2 1K, the third R3 270R, the problem is the third resistor, what does the "R" stand for?

Asked by nicobotha12345 8 years ago


ROTFLOL!! Yahoo Mail Vid

OK, sorry about forcing this on you, but it was just TOO FUNNY, Frodo and Gandalf text there way through LOTRVideocan not find yahoo video ID: https://us.ard.yahoo.com/SIG=14ureerp4/M=341232.12015912.12561458.6055752/D=regst/S=150001465:R2/Y=YAHOO/EXP=1207796968/L=.ITu8NG_XHKpuyVpR_1oogEBRF2HA0f9aMgADikv/B=KnQAQUSOxJE-/J=1207789768955420/A=5309423/R=0/SIG=11f551dpe/*http://overview.mail.yahoo.com/featured_video[https://us.ard.yahoo.com/SIG=14ureerp4/M=341232.12015912.12561458.6055752/D=regst/S=150001465:R2/Y=YAHOO/EXP=1207796968/L=.ITu8NG_XHKpuyVpR_1oogEBRF2HA0f9aMgADikv/B=KnQAQUSOxJE-/J=1207789768955420/A=5309423/R=0/SIG=11f551dpe/*http://overview.mail.yahoo.com/featured_video link to vid if embedding didn't work]

Posted by KentsOkay 10 years ago



BAATCH code - Math Problem?

Heey! I wanna make a .BAT program that'll help me do homework. I'm lazy to type the same formula to calculator, so I wanna make a program with preset formula. I wanna make the program solve this formula: S=3,14*r2 and O=3,14*d - Surface and Circuit of a cirle (I'm not english, my english's not the best). I wanna make the program solve these formulas. When you type r=3, it will say CIRCUIT IS (r*2 and then 3,14*'the r*2') AND SURFACE IS (3,14*r2 - the 2 should be in upper right corner) When you type d=3, it will say CIRCUIT IS (3,14*d) and SIZE IS (d:2 and then 3,14*'d:2 answer'2 - again, 2 in upper right corner. Please.......

Asked by NicoFilippo 2 years ago


need help with audio mixer? Answered

Hello . im going to make this mixer circuit.Im not sure if it work fine or not.Can you please check it for me ? Thank! In this schematic, i use R1=R2=47k Ohms , can i use a lower value like 10k or 4.7k ? http://i247.photobucket.com/albums/gg132/chipmapple/mymixer.gif

Asked by login721 6 years ago


i need somebody out there who could help me fix my controller?

I was playing and i dropped my new ps3 controller with the xbox360 button layout and the back r1 and r2 broke and i cant play. i payed about 70$ for it and ill pay 20$ if you can fix it.

Asked by keyoko8 6 years ago


if i put 3 resistors in line with each other does that add the resistance values together? Answered

What i mean is if they are like this in a circuit: > -R1- -R2- -R3- > becuase i need 300kohms, but all i have are multiple 100kohm resistors. if i put them like described above, will that equal 300kohms? if not, what way does?

Asked by zack247 7 years ago


Which Arduino is the Most Used by ibles Members ? Answered

I want to purchase an Arduino probably from Jameco Electronics close to me. There is some confusion on which revision R1, R2, R3 is the most compatible to this community.  Most of the Unos cost between $30 and $40 US. I use a PC with XP windows  later probably be getting a shield 8 pin.

Asked by iceng 6 years ago




50 papercraft robots

Holy moly! It's 50 papercraft robots in one place page! Check out this pretty sweet gallery of loads of future potential projects. I'm loving the R2-D2 myself, but many others look worth the time as well. Oh, if only that Obama one wasn't a one-off. Ah well. 50 Awesome Papercraft Robots via GeekDad

Posted by fungus amungus 8 years ago



Need to know if i can replace a 22 ohm /10% (1.5w ((I think due to size)) resistor with a 22 ohm / 2% 2watt.

The resistor placement is R2 in a Behringer B215D powered PA speaker. The resistor that was in it is smaller round than the replacement piece,but is the same length. The schematic does not state the wattage of the resistor so I'm a little confused. Any help would be greatly appreciated.  

Asked by hal.jensen.9 3 years ago


Arduino Multimeter on 1602LCD? Answered

Hi I am currently in the process of finishing the code for my Arduino controlled PSU with an LCD volt and amp meter. My question was basically, how can I get the volts and the amps to show on the LCD with 3 decimal place digits instead of 2 which i have now. Also, im having trouble putting 4 measurements all on one display- i currently have watts, amps and volts but i wanted to add resistance, however, for some reason i cant fit them all in one screen and i get weird errors when i try changing the setCursor value.  Thanks P.s here is the code I'm using (a took bits off different websites and examples-will reference them in the final sketch) #include const int numRows = 2; const int numCols = 16; LiquidCrystal lcd(12, 11, 5, 4, 3, 2); int analogInputVolts = A0; //voltinput int analogInputAmps = A1; //ampinput float vout = 0.00; float vin = 0.00; float amps = 0.00; float watts = 0.00; float ohms = 0.00; float VA = 4.970;          // Arduino 5V supply float R1 = 2995;        //  R1 in ohms float R2 = 999;        //  R2 in ohms int readAmpsADC = 0; int readVoltsADC = 0; void setup(){   Serial.begin(9600);   lcd.begin(16, 2);    pinMode(analogInputVolts, INPUT);    pinMode(analogInputAmps, INPUT);    delay(500);                    } float fmap(float x, float in_min, float in_max, float out_min, float out_max) {   return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min; } void loop() {    readVoltsADC = analogRead(analogInputVolts);    readVoltsADC = readVoltsADC + analogRead(analogInputVolts);    readVoltsADC = readVoltsADC / 2;    vout = (readVoltsADC * VA) / 1023.0;    vin = vout / (R2/(R1+R2));     delay(100);         readAmpsADC = analogRead(analogInputAmps);    readAmpsADC = readAmpsADC + analogRead(analogInputAmps);    readAmpsADC = readAmpsADC + analogRead(analogInputAmps);    readAmpsADC = readAmpsADC / 3 ;      // get average of 3 readings    amps = fabs(fmap(readAmpsADC, 509.0, 699.0, 0.0, 5.0));    if (amps    if (amps > 5) digitalWrite(13, HIGH);    delay(100);    if (vin          watts = vin* amps;    ohms = vin / amps;    Serial.print("Resistance-Ohms:");    Serial.println(ohms);    if (amps = 0.00) Serial.println("Nil");          lcd.print(" ");    lcd.print("V:");    lcd.print(vin);    lcd.setCursor(1, 1);     lcd.print("A:");    lcd.print(amps);   lcd.setCursor(0, 0);      lcd.print(" ");    lcd.print("W:");    lcd.print(watts);    lcd.setCursor(7,0);       delay(400); }

Asked by lightemmitingdiode 4 years ago


Where will the Instructables booth be at Maker Faire?

I missed the kick off ice cream social thing last night but I'm volunteering on Saturday at Maker Faire and really excited to see all the cool stuff.  I remember reading something about the R2-D2 area somewhere but when I look at the map I see an Autodesk area as well. I'm guess it'd be at the Autodesk area but if anyone sees this in time and has any info, please share. Thanks and maybe I'll see you there! 

Posted by sherrycayheyhey 6 years ago


Which resistors directly affect the frequency range?

I am currently working on an audio equalizer, and this is a link to the basic schematic I am using. http://www.daycounter.com/Filters/StateVariableFilters/State-Variable-Filter-Design-Equations.phtml If I am not mistaking, it would be the R1 and R2. I am also using Don Lancaster's book called the Active Filter Cookbook. I am confused on which equation I actually need to solve for the resistors using a certain frequency range. I am grateful for any help. Thank you.

Asked by sound91 9 years ago


Led flasher 555 delay-off help!?

I have a working 555 flasher circuit:  http://www.555-timer-circuits.com/flashing-led.html - i have added a switch between the + and the board, and replaced the R2 with a variable. Works great! Now i would like to add a "delay-off" function, if thats what it is called, so a single activation gives 10 seconds of flashing. So, any advice? PS: I have pnp & npn's, resistors etc, but no relay's. Thanks fella's!

Asked by R3born 6 years ago


Toshiba laptop windows Vista computer updated to windows 7 wifi not working? Answered

I updated my Toshiba Satellite P200 -R2 Laptop to windows 7. It installed properly but there is no wifi driver. The laptop doesn't detect the wifi hardware in it when i do a plug and play. Is there a package i'm suppose to download off of Toshiba? Is there a laptop version of Windows 7 i was suppose to buy? If so can i just download the package for it?

Asked by Aaamazzara 6 years ago


Model Train Track detector Updated twin-t model train track detector circuit parts list?

Model Train Track detector Does anyone know what the parts are for this updated twin-t model train track detector circuit? See Fig. 5-5 in "Easy to build Electronics Projects for Model Railroaders"I checked twice with the publisher for the missing parts list in the article but never got a reply. C1 - ?? , C2 -??, D1-D6 - ??, D7 - ?? Q1,Q2 - TIP 142 R1 - ??, R2 - ??,R3 - ?? Thanks, AB

Asked by brownart 7 years ago



DIY Instructables Handbook

I just had a great idea, different instructables people should make different handbooks for different subjects that they are good in. Those types of books at stores are usually really overpice and have a ton of information that you'll never use and just makes the book fatter. I'm personally making an electronic on, fitting 4 pages on one 8 1/2 x 11 sheet, making each sheet of the book ~3.25" X ~4.5. If you make one please upload a pdf file so that others can download it, cut it, and assemble it to have a crafty pocket refrence!This is the table of contents of electronic book (so far):TABLE OF CONTENTSFormulas....................................Definitions andSchematic Symbols....................Conversions................................Prefixes.......................................Resistor Code.............................Capacitor Code...........................Inductor Code..............................AWG Specifications.....................General Electronic Tips...............First page:General outline:E=VoltsI=CurrentR=ResistanceP=Watts (Power)L=InductanceC=CapatanceG=ConductanceOhms Law: E=IRPower Formula: P=IEResistors in series: Rtotal=R1+R2+R3...Resistors in Parallel:Rtotal=(R1-1+R2-1+R3-1+.....)-1orstill working on it (and the subscribts and superscripts didn't translate too well, but you get the idea.If you have any formulas that you want me to put in the electronics reference then post a comment!Some topics for references could be:WoodworkingConstructionCookingRadioetc.

Posted by guyfrom7up 10 years ago


Some advices on "self switcher circuit between battery & AC-DC ADAPTER power sources"

To put it shortly, I have small 12V 10A solar system (panels, car battery,  PWM charger, LEDs, car radio, car lighter (used for usb phone chargers etc) backed up with 12V 3A AC-DC adapter. They share common "ground" and outs connected in parallel but I dont want it to draw any power from AC adapter unless PWM controller shuts down power when battery gets empty. Anything below 500mah is neglible. I dont understand much about relays or microchips perhaps a relay design would be simpler and more efficient... So I tried to design a circuit with TIP33 transistor(because i found that it supports 10A continuous draw). but apparently it needs like 2V (max3) as Base-emitter voltage. if so, i need to add something between R1 and Adapter +12V and R4 and battery12V to reduce voltage to 2 volts... I have 3 questions 1st: is there any more efficient and relatively simple way to drop voltage withoutt leds? otherwise i will just use them as both indicators and voltage droppers since current will be lower than 20mah. 2nd: i am not sure if R2 and zener diode would be enough to let T2 draw all the current to keep TIP33 off while battery is on. perhaps i should remove R2 as well? 3rd: Since PWM and adapter both have reverse voltage and overload protection im planning to put a single diode to deny unnecessary current flow on R3 from battery.(i already removed the second one from design just before i write this here). i am thinking about putting resistor values to let only 30ma run there. Would that diode overheat while running on AC or drop voltage from adapter too much? R3=440 R1+R2=160 R4=anything depends on the T2(sth simple to handle 15-20mah C-E)

Asked by sailorondatea 4 years ago


Resistors for a NPN transistor? Answered

In the circuit diagram(which I've uploaded),I intent to use a NPN transistor(BC 547) as a relay.The 9 VDC is stepped down to 5 VDC by a LM7805 and should be the trigger to the transistor,completing a circuit which needs the 9 VDC.The Collector is given the common negative of both the voltages and the trigger gets the positive 5VDC.I need a bit help to calculate R1 and R2.I had used two random resistors previously but the Load got powered by the 9 VDC even before the trigger was applied to the transistor.I figured out that the problem might be related to the resistors used. (I haven't included the caps used at the terminals of the regulator in the schematic)

Asked by Adarsh_tronix 5 years ago


Can anyone make this and post an instructable? Answered

See the schematic and these are the parts and please make a breadboard version IC1: LM555 Timer IC Q1: 2N3906 PNP transistor R1: 100K potentiometer R2: 3.9 Kohm resistor R3: 10 Kohm resistor R4: 47 Kohm resistor C1, C3: 0.01-µF disc (non-polarized) capacitor C2: 1.0-µF electrolytic or tantalum (polarized) capacitor Speaker: 8-ohm, 0.5-watt speaker(i also tried a buzzer) Photoresistor: I used a LDR aren't they the same? The buzzer goes off(not off. it's like explosions"The bomb went off") when light hits the photoresistor.

Asked by Hafiz Mohammad Shayan Tariq 5 years ago


Laptop Fan Help!

So i bought a 2.8ghz laptop from a guy for $30i fixed EVERYTHING, invested about $200 of my hard-earned moneyand now the CPU fan wants to crap out on me >: ( the fan works, the circuitry that controls the fan has failed (on the mobo)so what i am asking is that you help me!i need to be able to regulate the 12v that comes from the battery into lower voltage, with a variable power supply, https://www.instructables.com/id/How-to-Build-a-Bench-Top-Power-Supply/I need someone to do the calculation so that i can regulate voltage form 4.5v - 12v what would be the resistance values?VOUT = 1.25 * ( 1 + ( R2/R1 ) )

Posted by Sandisk1duo 9 years ago


how can i make about 4 phone chargers directly from the solar panel which rates 24v and 20 WATS. Answered

Suppose I have got 4 cellphone of which each charges at 5.0V. and 500Am how can i design a 4x(+& -) branches where I can connect my charging pins? the solar panel produces 24V and 20 watts. Now I know 5.0vx4 is equals 20V means i have sufficient voltage. also voltage out = {(R2x volt(in)} / {R1+R2}.  are there some other formulas that I can use to solve the problem? please help!

Asked by Sheen Amon 5 years ago


Can't get a TLC272IP OP-AMP to work. what am I doing wrong? Answered

Hello I received this week a few TLC272IP op-amp and I wanted to test them. I created a circuit on a breadboard which looks like the attached image From what I read on the net, this is a  typical non inverting amplifier schema where gain should be (1 + R2/R1) I connected PIN 3 of the TLC272 to pin 3 of my arduino uno and using PWM I set the output to roughly 1V ("analogWrite(3, 51);") I used my voltmeter to read the voltage between ground and pin 3 and I could really see 1V  given I used R1 = R2 = 47k, I was expecting to have a gain of x2 and thus read voltage of 2V between pin 1 of the op-amp and ground  I get something that is very unstable, below 1V. I tried with 4 different TLC272IP I just got and get the same behavior. am I doing something wrong there? what do I miss? or do I need to review how op-amp are really working? (I purchased the TLC272IP because it's supposedly single power supply) thanks for any hint. JM PS. in some doc i read that I should not let the second op-amp in the air, so i tried as well by connecting pin 5 to ground and shorting 6 and 7 with a wire or a small 100k resistor but this did not change anything.

Asked by jm-l 3 years ago


I have some 50w HPLEDs I want to power. Any help on circuitry design will be wonderful!

The specs are Vf of 15-18V and 3200ma for one and 10-12Vf with 4000ma for the other.  I want to build it cheaply and maybe use the LM350 (?) and resistors (?). I'm going to use a 350W computer power supply since I got 2 of those lying around already. What resisters would I need to use and such?  Somewhere in a data sheet I found I should use a 120 Ohm for R1 but no clue how R1's rating will effect R2 in combination. I'm a novice at these things so lay it out in dumb mans terms =)

Asked by orbulon 8 years ago


How to make an BJT astable multivibrator run faster than 30Khz that works?

I am working on a dc to dc converter and it works but it seems to me that when i go higher than that it doesn't work anymore. I am using two C945 transistors. The resistor values for R1 and R4 are 1K and for R2 and R3 are 15k . For the capacitors C1 is 2.2nf and 1nf for C1. i have tried putting in smaler capacitors and increasing the two base resistor values. BTW its for a dc to dc converter that im working on. I also have no idea how much inductance on the inductor is. I am try to step up 6V dc to 15 V. It works put its low on power thats what i want.

Asked by josh1001 8 years ago


What's wrong with my circuit?

I have built this ne556 timer inverter with a few changes, R1 is now 470 ohm, R2 is now 3.3k ohm with a 10k pot, C1 is now a 470pF, and the Darlington transistors are now 2n3055s. I attached my multimeter to the circuit to measure frequency it should range from 150kHz to 450kHz with the 10k pot. While the pot was at zero (I think) the frequency was about 450kHz but when I started adjusting the pot the frequency went up to 1.1MHz, Why could this happening and how can I fix it? Also the 2n3055 on pin 9 was getting a lot hotter than the other despite their near exact conditions, why is this happening? I noticed when adjusting the pot that the frequency does drop to 360kHz then shoots up to 1.1MHz. Thanks!

Asked by The MadScientist 6 years ago


555 Timer Tone Generator. Which capacitor should I use, and where do I add the power source? Please help! Thanks!

I'm wanting to make a tone generator with a 555 timer that is a frequency humans can't hear. I'm going to follow this schematic. My R1 (potentiometer) will be 10k. R2 will be 33k. C1 will be .001mF. What should capacitor 2 be? And would the resistors i mentioned work for making a tone within the 17-20 Khz range? Also, how and where would I attach the power source? I'm thinking about using a 9 volt battery. Or would something else work better? I want it to be able to run for several hours straight. Thanks! http://www.reconnsworld.com/audio_tonegenerate.html? Thanks you!

Asked by darkforest 6 years ago


Help with DC motor control circuit

I am looking for some advice in regards to a DC motor control circuit i am trying to build out of some electronic parts I have lying around. See attached control circuit diagram.  The idea is that a timer will trigger the relay to either run the motor in reverse at full voltage or it will run forward stopping and starting as per the wave form from the 555 timer. So on for about 2 seconds and off for about 2 seconds. This waveform can be changed using R1 and R2 which are trim pots.  The circuit works as expected until I hook the motor up. When the motor is meant to be following the waveform from the 555 it will actually stop and start very erratically. Any help on the reason for this would be great.  Also this is one of my first electronics projects and any feedback on my design would be appreciated. 

Posted by jmullo 1 year ago


Capacitor charging circuit using bd243c. Will it work?? Answered

I recently made a schematic to charge a capacitor bank for my coilgun.D1-D4 are all 1n0007 t1 is a centre tapped transformer which will step up 12v to 330V. WIll it work. r1 and r2 are 10w resistors. Q1 and Q2 are BD243C with a rating of 65 watts.  i found my transformer from a very old cassette player. huge and heavy able to pump about 100W. i don't bother about charging time. I just want to know if it would be good. don't worry about the voltage monitoring i have a small voltmeter(like a watch. chinese product.) i am just want to know if it will work or not UPDATE: I have tried the shematic. It works flawlessly.  

Asked by ARJOON 7 years ago


What Apps/Utilities Do You Use Often/What's In Your System Tray?

My, system tray, in no particular order:Internet Call Director - I have dial-up so when someone calls me it disconnects the computer from the internets and reroutes the call to the phone.[pidgin.im Pidgin] - Awesome instant-messaging client. Compatible with about 15 different networks (MSN, AIM, ICQ etc.).My Dial-up internets connection icon.[opera.com Opera] - Opera web browser.Volume ControlAvira Antivir Personal Edition Classic - My antivirus program.Sound Volume Hotkeys - Use winkey + up/down arrow keys to change volume, handy when there's no volume dial (ie. headphones).WinRoll - Rolls up windows to their title bar, transparency, minimize any window to the system tray, stuff like that.[r2.com/au System Lock] - Click to password protect system. Hides everything on the desktop.What's in yours?

Posted by Aeshir 10 years ago


Velleman Sound to Light module LEDs always on.

I  have made the velleman sound to light project: http://www.vellemanusa.com/downloads/0/minikits/manuals/manual_mk103_rev1.pdf the LEDs are supposed to turn off when there is no sound and go bright when there are loud sounds. Mine are bright all the time. I first tried the kit using my own blue LEDs instead of the red ones supplied, these worked for a time then they just stated to give a VERY small amount of light. I switched to the red ones and now they are on high all the time. I also accidentaly connected R3 with C4 (see PDF). C1 and R2 are also connected by solder, im not sure if it should be like that, I also kinda damaged the C1 connection hole as I partially burnt it with my soldering iron D:.  Could any of these issues be the reason why my kit inst working? I have attached pictures of my board Many thanks, Rushmoore :)

Posted by Rushmoore 2 years ago