1. A flashing LED on one battery
Chip LM3909 allows the simplest LED control. The device operates from only one battery at 1.5 V and can provide a duration of up to 1 year when using a battery (cell) alkaline increased system capacity.
The circuit uses polar electrolytic capacitor C1 - 470 uF.
2. Flashing neon lamp
The circuit operates as follows. When low voltage neon lamp is off and has a high resistance. charging capacitor C1 slowly.
When the voltage across it increases up to the ignition voltage of a neon lamp, it begins to conduct current and light.
The neon lamp having a negative dynamic resistance, so by increasing the voltage flowing therein decreases. When reducing the voltage across the capacitor lamp extinguishes. Thus, there are periodic switching on and off the lamp.
The circuit uses 1 Mohm resistor R1.
3. switching LEDs
Shown below the switch circuit 2 LED-based timer 555 operates on 12 volts DC.
The LEDs are switched in opposite phase. If the output LC1 high voltage level, the illuminated LED D2 and a current flows through the resistor R2. At a low level at the output (pin 3) current flows through the resistor R1 and LED D1.
ON time T1 and T2 off timer status is calculated as follows:
T1 = 0,7 * (R3 + R4) * C1
T2 = 0,7 * R4 * C1.
Accordingly, the frequency of blinking LEDs will be equal to:
F = 1 / (T1 + T2).
In these formulas, the frequency is indicated in hertz, in seconds, the resistance - in ohms, capacitance - in farads.
4. Flashing LEDs for a model of a toy airplane
The scheme presented in the figure below used to simulate the "firearms" on the model of the toy vehicle.
The basis of the scheme - flip-flop on the chip NE555 type timer. Its powerful output allows connecting in parallel four LEDs (D1-D4) of increased brightness.
- R1-R4 - 330 ohms
- R5 - 2 MOhms
- R6 - 390 ohms
- C1 - 0.1 microfarads
- C2 - 100 uF
The circuit uses a DC power source BT1 9 V.