This device is a countdown timer specially designed for PCB exposure box.You can set how many minutes will be on UV light device , store this time in PIC’s EEPROM . Pressing start button lights are on until preset time ends. When lights are off an audible signal is heard. Microcontroller used is Microchip’s PIC 16F877. I used Mikroelektronika Mikropascal compiler to program the chip. Delay time 1-255 minutes.
Count down timer for UV PCB exposure boxes - [Link]
This is a good looking and practical device that can be useful in many areas where countdown timer is needed. This project is based on the PIC16F84A microcontroller. The time range can be adjusted between 1 and 999 seconds. This project has 3 buttons and one of them is named Set Button. In order to regulate the seconds up or down on the display you should press the Set button while pressing the button on the left or the right hand side. The author of this project is @Pedja089. More photos on Facebook Fan Page.
Timer from 1 to 999s with PIC16F84A - [Link]
Using a better antenna to improve DCF77 reception on long distances
We are in the prototyping phase of building a Nixie clock using 1N-14 Nixie tubes. The clock is designed around a PIC16F886 MCU, 74141N BCD decoder/driver and CNY74 optocouplers using common circuit topology. High DC voltage (+ 180VDC ) is generated using MAX1771 step-up switching regulator, which is quite efficient (if you use appropriate components).
Our clock will have some nice features:
- Compact design
- Manual time configuration
- DCF77 time synchronization
- Sync success indicator
- HV shutdown during sync (to reduce noise received by DCF module)
- Super-capacitor time backup
- Thermal protection
- ICSP connector etc.
When clock is complete we will release it as open source-hardware here at Electronics-Lab.com
We decided to use DCF77 signal as time reference for two main reasons, it’s quite easy to receive it and it’s very accurate for the reason that carrier signal is generated from atomic clocks.
But, what about receiving and decoding DCF77 signal? Read the rest of this entry »
This is a countdown counter based on ATtiny2313, primary developed for my PCB exposure box, but it can be used for other purposes too.
The counting range is between 1 and 90 minutes and it can be adjusted with up or down buttons (high and low in the pictures).
After the desired time is set, the countdown starts by pressing the start/stop button (on/off in the pictures). By pressing the same button we can interrupt the counting at any time we want.
After the count expires we hear a beeping sound and the load is disconnected. By pressing start/stop button we reset the counter and we are ready for another lap. All actions included the time remaining are shown in the LCD display.
Pcb countdown timer - [Link]
Matthias Franz writes:
The time manipulator is the little brother of the time signal transmitter located in Mainflingen close to Frankfurt in Germany. The very low frequency transmitter located there has an output power of 50 kW and is called, in accordance to its call sign, DCF77 (similar to HBG, MSF, RWM and WWV, WWVB, WWVH). The transmitter is operated by the Media Broadcast GmbH and transmits on 77.5 kHz the official time signal for Germany. The medium range is stated with 2’000 km.
My time manipulator however offers some more functionalities. It’s the true alternative if you have difficulties to find your flux capacitor or your local electricity supplier canceled your contract after you had difficulties to pay off for the 1.21 GW.
Homemade 77.5 kHz DCF77 time signal transmitter - [Link]
I was looking for, what I thought, was a simple clock/timer design. Something with a remote and a big display that could be read from across the gym and that I could program with up/down counting but also intervals specific to CrossFit like Fight Gone Bad or tabatas. I wanted to incorporate a bell to give it a gym feel and something that could be heard over loud music. This journey took me through many designs, chips, a custom board, wood working and a whole lot of learning!
Arduino CrossFit Timer - [Link]
Charalampos Andrianakis writes:
Two years ago i modified a scanner replacing its mechanism and all the internal electronics with UV lamps converting it to an UV exposure box for PCB prototyping. By the need of making my life easier and not waiting for the pcb to be exposured i designed an AVR timer to automatic switch off the lamps after 1 minute of exposure which was much enough for the PCBs. Here is the circuit
This was one of my first completed projects from design to production. As you can see the scheme isn’t that good and there have been by passed some capacitors at the power supply. But the circuit works with no problem.
AVR Switch Timer - [Link]
Goal is to replace this Ikea super cheap timer that works … well, as good as something manual that you paied less than 200 JPY (less than 2 euro). Not precise, sometimes doesn’t ring, or ring just the blink of an eye, so easy to miss…
The new timer will:
- Have a graphical LCD (bought one one year ago, never used it, needed a pretext, so…)
- Work on battery (1x 9v battery)
- Play music when it’s time
- Use a speaker and amp
- Possibly use a YMZ294 ?
- In fact something else but much better…
- Have an on/off system with a push-button, not a open/close switch In fact a tilt switch
- No arduino, but a simple atmega 328 (more than sufficient)
- Keep me busy a few days while allowing me to use some parts I bought long time ago and create a un-reasonable and out of price kitchen timer
Arduino KitchenTimer - [Link]
ISS tracking theme clock face – Monochron Clock Kit. SPACECHRON, Scott writes – [via]
Some of my christmas money went towards purchasing a Monochron Clock kit from Adafruit.com.
It turned out to be an awesome build and I had lots of fun putting it together. I also chose it because it allows you to program your own clock “faces” for it. I’ve programmed a Space themed face for it that simulates the space station ground track. I’ve also programmed an autodim feature for the backlight because my preferred daylight brightness was too bright at night. The fact that I can customize it to fit my needs is an awesome thing. I wish there were more products like it.
ISS tracking theme clock face – Monochron Clock Kit - [Link]