Simple LED Bike Light Schematic

We know flashing LED lights from the high street shop. But, they were often gave me trouble with flat batteries and lights that fell off. In this case, we make a better one idea using another front wheel, one which has a dynamo already built in the hub. This supplied a nice sine wave of 30 Vpp (at no load). With this knowledge I designed a simple power supply. The transistors that are used are type BD911. These are a bit of an overkill, but there were plenty of these at my school, so that is why I used them. Something a little smaller will also work. The power supply is connected to an astable multi-vibrator. This alternately drives the front light and the rear light. This is the figure of the circuit.

Simple 220V Soft Start Schematic Circuit

Here’s In particular, the power supply with a high value capacitor is used in SMPS circuits in the 220V soft start circuits, as in most of them, this circuit has a simple structure and is designed to operate by directly regulating 220v without transformer. Here’s a figure of the schematic.

Current Source for Grounded Load Circuit

This is a design for a current source (as opposed to current sink) for driving a grounded load can be a bit awkward. Admitedly the suggested circuit cheats a little in that the load is tied to virtual grounded, so it’s still potentially useful. This is the figure of the circuit

Two control loops are involved here:

Opamp A1 maintains the ‘cold’ end of the load at virtual earth and

A2 sets a current I = –V1/R1, which also flows through the load R_L.

DS18B20 Temperature Sensor Circuit

This is a sensor to detect the temperature. This sensor can be programmable to sensor device. This device can operate using power supply 3V to 5V VDC and have temperature range -55°C to +125°C with accuracy ±0.5ºC. In programmable system, this device has output Resolution: 9-bit to 12-bit and unique 64-bit address enables multiplexing. This sensor is a waterproof sensor. This is the figure schematic for the sensor using DS18B20.