Search results

  1. N

    Snubber circuit

    I'm working on 'improving' the Kettering system on my 1948 tractor. (Max 2000 engine RPM and 3 amps to the coil) Initially I was going to use an ignition IGBT, such as the ISL9V5045S3ST_F085, which has all of the snubber circuitry already built in. The problem is that the only practical way to...
  2. N

    Are UJT's used anymore?

    I have a circuit diagram for a CDI trigger circuit circa the 1970's, that uses a 2N1671 UJT. Newark is the only place I can find them but at $84 each!! Looking around for an alternative that's not solid gold and jewel encrusted it seems that UJT are a thing of the past. Mouser only lists 2 and...
  3. N

    TO-220 to SMD

    I bought a cheap BMS module for my headway LiFePo4 cells which was supposed to balance the cells and protect from over current charge and discharge. It didn't, but instead fried two of my headway cells and one of it's own power mosfets. Looking up the mosfet number it was a obsolete Toshiba part...
  4. N

    MCU voltage regulator

    Remember I'm a newbie for electronics and have only just started using PIC and Atmel microcontrollers in my simple learning projects, but a question. Why don't microcontrollers have a voltage regulator built into the chip? I have some old A3141 hall sensors that can take an input voltage of up...
  5. N

    Removing transformer sealant

    I have a small PCB mounted transformer from a power supply which I'm going to rewind. It has 'E' 'I' laminates which have been coated in some sort of resin. I don't think it's an epoxy as it looks like it was dipped and has a very thin layer of a slightly yellow brittle material. So far i've...
  6. N

    Diode choice

    This is to total newbie question that I can't find an answer to. I'm using the 1980 National Semiconductors Voltage Regulator Handbook to design a simple regulated 5 volt output power supply for my old tractor. One of the first items in the input part of the circuit, as in most similar circuits...
  7. N

    Thyristor question

    Part of my CDI project involves sending a 20mA pulse to the gate of a TYN612M thrystor to discharge the storage capacitor. The spec sheet gives a minimum of 1.5mA and maximum of 5mA to turn it on, but gives no latching current. The circuit works perfectly and the gate gets the full 20mA, but the...
  8. N

    Hall switch magnets.

    I've been messing around with the ignition system on my old Ford 8N tractor for a while now and the stumbling block in any design has always been the points. So I decided to build a hall sensor switch, possibly an Allegro A3144, because I already have a bag of them. I made a PVC sleeve to go...
  9. N

    Programming starting point

    A very general question. When you have come to the point in a project where you need to write code, how do you begin. By that I mean do you start by using pencil and paper or do you dive straight in with a software package like flow code? For the younger members of the forum, pencils and paper...
  10. N

    IGBT current limit

    I still haven't mastered posting circuit diagrams but my circuit is simple and easy to describe. The purpose is to limit the current through a 1.58mH ignition coil to 4 amps. The coil is driven by a Fairchild IGBT specifically used for ignition coils so all the spike suppression is already on...
  11. N

    rand function in AVR C

    This is a section of code that's giving me problems in a project and I can't work out why. The purpose is to use the rand function to generate a number between 1 and 100 then use this number to randomly alter the delay time that an led is on. #include <util/delay.h> #include <avr/io.h> #include...
  12. N

    328P datasheet

    Due to ignorance and not taking sufficient time I've managed to brick an Atmega328, well a couple of them actually. Of course there are various commercial and DIY fuse doctor programmers on the web, but just copying and pasting Arduino code doesn't help me learn anything. So I decided to write...
  13. N

    Electronic math

    A 62 year old student question. I keep coming up against the stumbling block of my limited mathematics knowledge which is holding me back. Yes I understand Ohms law, but anything after that I'm having to learn from scratch. After all they taught me algebra nearly 50 years ago, and I wasn't...
  14. N

    EBay stores

    If I'm in no hurry to get components I gravitate to EBay's offerings from the far east, and I'm sure I'm not alone, It seems silly to buy things like Pro Mini Atmega boards for $10 locally when I can get 5 of them for the same price with free shipping. Recently I have been price shopping for a...
  15. N

    Voltage regulator question

    My project is to be used on an old 1949 Ford tractor. Incredible performance of 0-60 in about 3 weeks:D The unfortunate thing is the ignition system is so noisy that a radio will pick up the interference from about 5 yards away, but I want to use a micro-controller! I read the National...
  16. N

    Banging my head on a wall

    I have designed the electronics for the ignition system for my old 49 tractor, but have come up against a brick wall with the coding for the Arduino. It simply didn't work, and after repeatedly simplifying the code to find the problem, I found that I can never get a valid input from the pin...
  17. N

    Code in setup section of a sketch

    Can it be done? I am learning to use the Ardunio Uno as I work on my project and believe this may be an easy way round a problem. I am working on the ignition of my old tractor and will be using hall effect sensors to fire IGBT's. My stumbling block is: what if when I turn on the ignition the...
  18. N

    Old tractor ignition upgrade problem

    So here's my project I have a 1949 Ford 8n tractor, 4 cylinder side valve with 6volt electrics, which the previous owner converted to 12volts and used a regular GM alternator instead of the generator. This is a common conversion but leads to problems with the ignition. The distributor is on the...
  19. N

    Another newbie

    Hi all. I've been interested in electronics since I was a kid, but never pursued it any further than reading. After years as a cop I finally retired, and now have both the time and money to pursue my hobbies. Well more time than money, police pensions are pitiful. Looking forward to asking a...
Top