Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  
Author: Subject: Ignition coil drivers
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 18-4-2004 at 14:55
Ignition coil drivers


Hello everyone, I have read much of the labs on the powerlabs website. I found the ignition coil driver to be really cool. I so far have managed to salvage an ignition coil, a 12v power source, and some capacitators out of a 480v HPS light. I have done some searching and haven't really been able to find and details on assembling the device. I wish I could see a copy of that magazine the guy used as a guide to build his. If anyone has any experience or information on how to construct one of these ignition coil drivers I would greatly appreciate some advice. Heres a link just incase you don't know what i'm talking about.http://www.powerlabs.org/igncoildrivers.htm



N/A
View user's profile View All Posts By User This user has MSN Messenger
axehandle
Free Radical
*****




Posts: 1065
Registered: 30-12-2003
Location: Sweden
Member Is Offline

Mood: horny

[*] posted on 19-4-2004 at 10:18
Here


http://www.geocities.com/CapeCanaveral/Lab/5322/coildrv.htm

It has a minimum of components, and is easily built. If you use a high wattage powersource, use a bigger transistor and don't forget to put it in a heat sink.

I've built this one, and can vouch for that it works. The trimpots are good, since they allow you to adjust the frequency to avoid radio interference.




My PGP key, Fingerprint 5D96 E09E 365D 1867 2DF5 C2FE 4269 9C19 E079 CD35

\"Verbing nouns weirds the language!\"
View user's profile View All Posts By User
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 20-4-2004 at 19:01


I noticed that the 2N3055 NPN power transistor seemed to have 3 pins on the schematic. However, went I went to the store the 2N3055 NPN power transistor only had 2 pins, am I reading something wrong?



N/A
View user's profile View All Posts By User This user has MSN Messenger
Axt
International Hazard
*****




Posts: 778
Registered: 28-1-2003
Member Is Offline

Mood: No Mood

[*] posted on 20-4-2004 at 19:49


The third "pin" is the metallic base of the transistor, the base is likely to be the "collector". This is the one that will get hot!


[Edited on 21-4-2004 by Axt]
View user's profile Visit user's homepage View All Posts By User
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 20-4-2004 at 20:49


So what i'm supposed to solder a wire to the base of the transistor? By the way, whats the point of having 2 potentiometers?

[Edited on 21-4-2004 by tom haggen]




N/A
View user's profile View All Posts By User This user has MSN Messenger
Axt
International Hazard
*****




Posts: 778
Registered: 28-1-2003
Member Is Offline

Mood: No Mood

[*] posted on 21-4-2004 at 00:45


Connect it under the bolt you will use to fix it onto the heatsink.

Potentiometers look to be used to let you tune the frequency of the discharge (as axehandle said), but im sure there are more qualified people here to give you a more "technical" answer.
View user's profile Visit user's homepage View All Posts By User
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 21-4-2004 at 06:51


I know what a potentiometer does, I just don't know why theres 2 of them in the circuit. Also, i'm using a wireless bread board, so I think I will just solder a wire to the base of the transistor. I will accomplish the same task.



[Edited on 21-4-2004 by tom haggen]

[Edited on 21-4-2004 by tom haggen]




N/A
View user's profile View All Posts By User This user has MSN Messenger
Axt
International Hazard
*****




Posts: 778
Registered: 28-1-2003
Member Is Offline

Mood: No Mood

[*] posted on 21-4-2004 at 07:07


Just know that it will get VERY hot, a heatsink is VERY recommended! Even if solder was to stick to the base (dont think it will), the heat may even melt the solder off. Ive set things on fire with those transistors in simular circuits.

If you twisted a wire through the hole in the base of transistor and soldered the wire together you may get away with short runs.

EDIT: The powerlabs site you linked to shows the transistor in place on a heatsink. That would be the same transistor, correct?

[Edited on 21-4-2004 by Axt]
View user's profile Visit user's homepage View All Posts By User
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 21-4-2004 at 08:11


Ya ok that is the same transistor i'm using. Well I don't have a heat sink. I think i'm just going to get my circuit running as I have yet to do that. Once I play around with it, doing some short runs like what you were saying. I guess I will have to get some type of heat sink before I try to enclose the project. I hope my solderless bread board doesn't melt.

[Edited on 21-4-2004 by tom haggen]




N/A
View user's profile View All Posts By User This user has MSN Messenger
axehandle
Free Radical
*****




Posts: 1065
Registered: 30-12-2003
Location: Sweden
Member Is Offline

Mood: horny

[*] posted on 21-4-2004 at 08:56
improvised heat sink


You can improvise a heat sink. Take a piece of Al plate, make 4 cuts from the corners in the direction of the center, then bend the outsides in a 45 degree angle upwards. Drill holes for the emitter and base leads, and larger holes for the fastening bolts. Use normal thermal paste between the transistor and Al plate.

It will get awfully hot very quickly without a heatsink.

Quote:

Connect it under the bolt you will use to fix it onto the heatsink.

I'd recommend this as well. We're talking very high currents here.


[Edited on 2004-4-21 by axehandle]




My PGP key, Fingerprint 5D96 E09E 365D 1867 2DF5 C2FE 4269 9C19 E079 CD35

\"Verbing nouns weirds the language!\"
View user's profile View All Posts By User
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 21-4-2004 at 09:50


Could you recommend some dimensions for the aluminum sheet metal I should use. Also, I thought the 2 leads comming out of the transistor were the emitter and collector. I believe the exterior of the transistor would be the base in this type of transistor.



N/A
View user's profile View All Posts By User This user has MSN Messenger
axehandle
Free Radical
*****




Posts: 1065
Registered: 30-12-2003
Location: Sweden
Member Is Offline

Mood: horny

[*] posted on 21-4-2004 at 11:23


Well, my commercial heat sinks seem to be about 2mm thick. But any thickness is better than no heatsink. As for which is B, E, and C, I don't remember.



My PGP key, Fingerprint 5D96 E09E 365D 1867 2DF5 C2FE 4269 9C19 E079 CD35

\"Verbing nouns weirds the language!\"
View user's profile View All Posts By User
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 21-4-2004 at 14:28


ya i Guess I'll research my particular transistor and try to find out which is which.



N/A
View user's profile View All Posts By User This user has MSN Messenger
hodges
International Hazard
*****




Posts: 509
Registered: 17-12-2003
Location: Midwest
Member Is Offline


[*] posted on 21-4-2004 at 15:19


Quote:
Originally posted by tom haggen
I know what a potentiometer does, I just don't know why theres 2 of them in the circuit.


In that circuit, two potentiometers are used in order to allow both the on time and the off time of the pulse to be varied. Think of a square wave. If it has a frequency of 1kHz, and has a 50% duty cycle, it will be on for 0.0005 seconds and then off for 0.0005 seconds then on for 0.0005 seconds, etc. Now if you adjust the frequency to 5KHz, the wave will be on for 0.0001 seconds and off for 0.0001 seconds. But the coil may work better with some value other than 50% for the duty cycle. Maybe it wants to current flowing twice as long as it is off. In that case, for a 1KHz signal, it would be on for 0.00033 and off for 0.00066 seconds. There are two potentiometers because one adjusts the on time and the other adjusts the off or total time.
View user's profile View All Posts By User
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 21-4-2004 at 21:30


Thanks for clearing that up hodges. I'm a little rusty with my electronic skills. One thing that I have another question about is this. On the schematic there is a positive and a negative on the ignition coil. What leads are supposed to create the arc of electricity?

[Edited on 22-4-2004 by tom haggen]




N/A
View user's profile View All Posts By User This user has MSN Messenger
hodges
International Hazard
*****




Posts: 509
Registered: 17-12-2003
Location: Midwest
Member Is Offline


[*] posted on 22-4-2004 at 14:47


The ignition coil will have 3 connections, +,-, and spark. The high voltage is between the spark (top terminal, which has the recessed contact) and -.
View user's profile View All Posts By User
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 22-4-2004 at 15:13


Once again, a million thank yous to everyone. I will try to post a picture if I ever get this project going.



N/A
View user's profile View All Posts By User This user has MSN Messenger
axehandle
Free Radical
*****




Posts: 1065
Registered: 30-12-2003
Location: Sweden
Member Is Offline

Mood: horny

[*] posted on 22-4-2004 at 18:27
Heatsink.


NP. Just get a huge heatsink. Look at mine:





My PGP key, Fingerprint 5D96 E09E 365D 1867 2DF5 C2FE 4269 9C19 E079 CD35

\"Verbing nouns weirds the language!\"
View user's profile View All Posts By User
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 22-4-2004 at 19:32


Right on, I'm having trouble trying to get the circuit working properly. I'm hoping to get some advice from one of my old instructors soon.

[Edited on 23-4-2004 by tom haggen]

[Edited on 23-4-2004 by tom haggen]




N/A
View user's profile View All Posts By User This user has MSN Messenger
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 7-2-2005 at 11:52


Some how I had problems last time I tried wiring this circuit. My 555 timer was destroyed last time I hooked every thing up. Anyone have any idea what might have caused this?

Basically, I took this same circuit, removed the transistor part. I used 2, 1000 ohm resistors, and also I hooked up an L.E.D. to terminal 3 of the timer. I also switched to a 220uF capacitor. Basically I had a circuit that enabled you to see a blinking L.E.D. Then I removed the L.E.D. and hooked up that transistor and the ignition coil in their correct places. When I hit the power it fried my 555 timer. Any ideas?

[Edited on 7-2-2005 by tom haggen]

[Edited on 7-2-2005 by tom haggen]




N/A
View user's profile View All Posts By User This user has MSN Messenger
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 7-2-2005 at 12:14


Here's a picture of the circuit which just has a blinking L.E.D.

IMGA0179.JPG - 136kB




N/A
View user's profile View All Posts By User This user has MSN Messenger
Eclectic
International Hazard
*****




Posts: 899
Registered: 14-11-2004
Member Is Offline

Mood: Obsessive

[*] posted on 7-2-2005 at 13:56


Probably it's an inductive kickback voltage spike. When your circuit tries to turn off the current flowing through the coil's primary circuit, the magnetic field collapses and generates high voltage. It acts as if the electricity has inertia and "wants" to keep flowing in the same direction. The way to fix that is with a fast diode across the coil primary that will block the charging voltage and short out the inductive kickback. Also make sure your high voltage terminal is going to ground and not the transistor switch when you draw a spark.
View user's profile View All Posts By User
hodges
International Hazard
*****




Posts: 509
Registered: 17-12-2003
Location: Midwest
Member Is Offline


[*] posted on 7-2-2005 at 14:42


You also should put a large (at least 200uF) capacitor in the circuit across the power supply (battery) leads. I had a similar circuit that would sometimes blow out the chip when power was first connected or disconnected. Adding the capacitor solved the problem.
View user's profile View All Posts By User
tom haggen
National Hazard
****




Posts: 488
Registered: 29-11-2003
Location: PNW
Member Is Offline

Mood: a better mood

[*] posted on 7-2-2005 at 15:20


So I need to use to capacitors for the ignition coil circuit?

I should also mention that I was never actually able to get an electrical arc.

[Edited on 7-2-2005 by tom haggen]




N/A
View user's profile View All Posts By User This user has MSN Messenger
Pommie
Hazard to Self
**




Posts: 70
Registered: 6-2-2005
Location: Australia
Member Is Offline

Mood: No Mood

[*] posted on 14-2-2005 at 16:06


Quote:
Originally posted by tom haggen
So I need to use to capacitors for the ignition coil circuit?

I should also mention that I was never actually able to get an electrical arc.

[Edited on 7-2-2005 by tom haggen]


You need to add a diode to get rid of the back EMF from the coil. I would suggest a 1N4004. It should be connected like this.



You also mention earlier that your transistor has the case as the base. If this is correct then I would guess it's not a high current device and suggest you go get a 2N3055.

HTH

Mike.
View user's profile View All Posts By User
 Pages:  1  

  Go To Top