LibreTimeBase: Rubidium clock control board

Schematic PCB

555 timer: 4MHz (80 meter band) CW transmitter

Might not be an actual working transmitter, but it does produce a few mW of RF power at 4 MHz using only two LMC555s.
Principle of Operation (see attached simplified schematic):
At lower operating voltages, the flip-flop (TR) input of the LMC555 can be used as an inverting comparator input to control the output of the device. This requires the Threshold (TH) input to be active (high). This circuit applies a DC bias at the switching threshold of TR and superimposes a small AC feedback signal to create an oscillator. An inverted version of the same signal is applied to the second LMC555 to produce two complementary open collector outputs (the device's discharge output). The output is then connected as a standard push-pull RF amplifier. The TH input is used as the enable input to key the transmitter.

Schematic PCB

555 timer breathing light, yes, yes, yes!

Introduction: Third Prize in the 2022 Guangzhou City Polytechnic School of Electrical Engineering Electrical and Electronic Breathing Lamp Design Competition

Schematic PCB

ne555cd4017 water lamp

Introduction: The familiar NE555 and CD4017 water lamp, but this time it is made into a ring, and all the components are plug-in, which does not require a high welding threshold and can be used for viewing and practicing welding skills.

Schematic PCB

NE555 disconnection alarm

Introduction: Disconnection alarm made using NE555

Schematic PCB

UPS backup power control board

Introduction: Use the hysteresis circuit of 555 to complete the automatic charging and discharging function of the battery.

Schematic PCB

5V proximity switch

Introduction: Adjust the original 12V powered infrared proximity switch to 5V to adapt to the current mobile phone charger head. It is very convenient to use as a module.

Schematic PCB

Design of seven-tone electronic piano based on 555 timer

Introduction: Seven-tone electronic piano based on 555 timer

Schematic PCB

Flowing water and ice

Introduction: The running water lamp Bingdundun made using 555 timer

Schematic PCB

Guangzong Yaozu

Introduction: Third Prize in the 2022 Guangzhou City Polytechnic School of Electrical Engineering Electrical and Electronic Breathing Lamp Design Competition

Schematic PCB

Ultrasonic nebulizer (based on NE555)

Introduction: You can find a lot of relevant principles on Baidu, so I won’t go into details here.
Please see the BOM table for device selection. The piezoelectric ceramics were bought on Taobao with a center frequency of 113KHz.
Frequency adjustment is achieved by adjusting the potentiometer. Be careful not to touch the working piezoelectric ceramics with your hands.

Schematic PCB

555 electronic keyboard

Introduction: la la la

Schematic PCB

555 chip speed regulation

Introduction: 555 chip makes dimming and speed control, classic PWM. I originally wanted to use a ready-made one, but I made one that my brothers made public, but it didn’t work, so I had to draw it myself.

Schematic PCB

drsstc/sstc fixed frequency/music optical fiber arc extinguishing

Introduction: Arc extinguisher for Tesla coil

Schematic PCB

[Power bank low current anti-power-off plug-in]

Introduction: It is a power bank plug-in designed to prevent the power bank from automatically cutting off power when supplying power at low current (mostly <50mA). In this way, the power bank can be completely drained. . .

Schematic PCB

Effector analog switch bypass

Introduction: 555 controls the CH443K analog switch, used for signal switching of guitar effect pedals

Schematic PCB

BD-2 RealPass

Introduction: Boss BluesDriver-2 electric guitar overdrive effector true bypass version

Schematic PCB

AB-BOX

Introduction: Guitar effects chain switcher

Schematic PCB

Lucky wheel lottery DIY production electronic 555 production

Introduction: The Lucky Wheel is a tool that predicts where the rotating disk will stop when it stops. It can also be used as a number estimation game, electronic dice, lottery machine, etc.

Xue Qiankun-202110512046-Electromechanical

Introduction: Panzhihua University Electronics Association EDA trains outstanding students on open source projects

Schematic PCB