Dave celebrates the classic 555 timer IC by building the Evil Mad Scientist “three fives” discrete timer kit. Some scope measurements and an explanation of the internal 555 timer circuitry follow.
EEVblog #555 – 555 Timer Kit - [Link]
This is a collection of Maxim’s newest real-time clock ICs.
This real-time clock IC operates with very low current and is compatible with high-ESR crystals for a space saving, low-cost design. Read the rest of this entry »
The TS3004 is a single-supply, timer IC fully specified to operate over a supply voltage range of 1.55V to 5.25V while consuming 1.9μA supply current. Requiring only a resistor to set the base output frequency (or output period) at 25kHz (or 40µs) with a 50% duty cycle, the TS3004 timer/oscillator is compact, easy-to-use, and versatile. Optimized for ultra-long life, low frequency, battery-powered/portable applications, the TS3004 joins the TS3001, TS3002, TS3003, TS3005, and TS3006 in Touchstone’s CMOS timer family.
TS3004: A 1.55V TO 5.25V, 1.9µA, 0.005Hz TO 300kHz RESISTOR-TUNABLE TIMER IC - [Link]
Kerry Wong documented his VFD filament driver built:
I recently salvaged a vacuum fluorescent display (VFD) from a piece of old test gear. The VFD is a 13 digit 7-segment multiplexed display and I thought it would look great in a custom digital clock or something similar. While it has the model number FUTABA 13-MT-54NA, I could not find any information on the internet specifically for this model. Of course, before I could put this vacuum fluorescent display to use in my final project, I needed to first build a driver circuit to drive this display.
VFD filament driver using 555 - [Link]
The goal of this project is to construct a simple 0-9999 seconds count down timer with an alarm and a display. The time is set through two tact switches and the count down seconds are displayed on a 4-digit seven segment LED display. The project uses PIC12F683 microcontroller for all I/O and timing operations and MAX7219 IC for driving the seven segment LED module. The time out condition is indicated by an audible alarm from a buzzer.
0-9999 seconds count down timer using PIC12F683 microcontroller - [Link]
Haris Andrianakis writes:
After some modifications on my UV exposure box (scanner) for better UV expose, i desided that a better pcb must me designed for switch timer. The old one had over drilled holes and it was designed and built on my very fist steps. Also the high voltage side from the low voltage wasn’t seperated as it needed to be safe.
So i redesigned it in a more compact and easier to use pcb. The firmware has been also updated and now you can program the timmer by using the two buttons. The time is calculated by timer interrupt triggering using a 32.768KHz RTC Crystal with better accuracy. The display update also has been changed from static to dynamic.
PCB Exposure Switch Timer V2.0 - [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]
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]
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]