How can I calculate a Joule Thief circuit
#joule thief
#boost converter
#low voltage
#energy harvesting
#transistor
#ferrite core
#LED
#battery
#efficiency
#DIY electronics
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Current Dimmer for white 24 LED array
This simple linear circuit provides continuously variable regulated current (~25-400mA) from a 4-6 Volt source. The linear design is chosen for simplicity, reliability, ease of repair, and to avoid switching EMI in cave radios. The circuit requires only 0.2V headroom...
Transistors UHF tuner circuit
The circuit features an adjustable prestage utilizing the AF279 transistor, while the natural oscillation mixer stage employs the AF280 transistor. The power circuit is mounted on a board with copper coating. The main coil specifications are as follows: L1, L3,...
White LEDs Flashlight
Here is a schematic of a rechargeable 9-LED flashlight using two Gates SLA cells and nine LEDs. It is as bright as when the single bulb was used, and lasts 3 times longer per charge. That is about 10 hours...
LED Color Fade Effect circuit diagram
This circuit creates an LED color fade effect. As indicated by the name, the light intensity of the LEDs in this circuit transitions from high intensity to low intensity and eventually turns off. A 30 µF capacitor and a 100...
Transistor common emitter amplifier circuit
The circuit is a bias circuit for automatic stabilizers that maintains a stable quiescent operating point with good thermal stability. It utilizes a three-pole tube with an NPN type transistor, characterized by a small Iceo. An adjustment potentiometer, RP, is...
The time delay circuit diagram composed of transistor
The circuit is designed to set a delay time based on the voltage Us and the resistor R. In this configuration, S1 acts as the discharge switch for capacitor C. When switch S1 is closed, the stored charge in capacitor...
Single-junction transistor a phase-shift trigger circuit
Figure 16-29 (a) illustrates the trigger output through a resistor R2, while Figure 16-29 (b) depicts the integration of a programmable unidirectional transistor (PUT) trigger circuit. The adjustable potentiometer RP can modify the conduction angle of the TRIAC to facilitate...
BCD seven sections of nixie tubes reveal the decoder circuit
The luminescent diode (LED) is constructed from gallium arsenide (GaAs), a specialized semiconductor material, and gallium arsenide phosphide. It can be used individually or assembled into segment-type or lattice LED display devices. The display unit consists of a sectional type...
Battery-splitter
A common requirement in many systems is to obtain both positive and negative supplies from a single battery. For applications with small current needs, the circuit illustrated provides a straightforward solution. It generates symmetrical output voltages of ±, each equal...