Super bright LED mini desk lamp

The ultra-bright LED mini desk lamp has the characteristics of zero radiation, zero pollution, zero flicker, uniform lighting, stable brightness, low light decay, and closer to natural light. The ultra-bright LED is an energy-saving light source with broad development prospects.

The circuit working principle of the mini desk lamp circuit is shown in Figure 1. In the figure, VD1 is a diode to prevent reverse charging, that is, when the voltage polarity of the external charger is reversed, the charging function is blocked to prevent damage to the charger and circuit. R1 and LED10 form a charging light-emitting indication circuit. R2, VT, R4, and LED11 form a fully charged light-emitting indication circuit. GB uses two No. 7 1.2V nickel-hydrogen rechargeable batteries. S is the desk lamp switch, L1 is a boost energy storage inductor coil, VD2 is a boost freewheeling diode, C1 is a filter capacitor, and IC1 is a DC/DC boost integrated circuit dedicated to ultra-bright white light-emitting diodes.

LED1~LED9 are super bright light emitting diodes.

The core component of this circuit is IC1 (12100A), which is a DC/DC step-up integrated circuit in a micro SOT-89-3 package. It can increase the voltage below 1V to above 3.3V, providing the working voltage for the ultra-bright LED light-emitting diodes. When in use, just turn on the small desk lamp switch, and the 9 ultra-bright LEDs will shine brightly. When charging, the charging circuit can only work when the positive pole of the external charger is connected to the positive pole of VD1; when the polarity of the external charger is reversed, due to the blocking effect of the diode VD1, no current passes through the circuit and it cannot work, eliminating the possibility of damaging the charger circuit after the charger is reversed. When the polarity of the external charger is connected correctly, there is current passing through R1 and LED10, and the light-emitting tube indicates that it is charging. At this time, because the battery voltage is lower than 2.7V, VT is not turned on, and the full indicator LED11 is not on; as the charging time continues. The voltage of GB gradually increases. When it rises to above 2.7V, VT is turned on, and LED11 lights up, indicating that the battery voltage is full. It can be seen from the circuit that the conduction condition of VT is Ub1＞Ue1, Ub-Ue=0.7V. Since LED11 is connected in series to the e-pole of VT, UD11 uses an ordinary light-emitting diode that is lit with a voltage of 2.0V. Therefore, the voltage for lighting LED11 is 2V+0.7V=2.7V.

Instructions for use See the title picture for the actual picture of the mini desk lamp. The right side of this mini desk lamp is equipped with a two-speed toggle switch and a DC-005 charging socket. There are two red and green indicator lights on the top. The red indicator light is the charging indicator light, and the green light is the charging completion indicator light. When the battery power is low, connect an external +5V power supply to charge the battery. At this time, the red indicator light is on. If the green light is on after a period of time, it means that the battery charging has been completed.

Energy saving effect This mini desk lamp uses 9 new ultra-high brightness white LEDs as the lighting source. The power of an ultra-high brightness LED is about 50mW when it is working normally, so the power of this mini desk lamp is less than 0.5W. The power of ordinary desk lamps is generally 5W to 20W, and the power consumption of this mini desk lamp is less than one tenth of that.

The shell of the small desk lamp is made of a discarded computer optical mouse (keeping its three buttons and removing other components on the circuit board), the support rod uses the snake skin tube from the old earphone, the switch S uses a two-speed toggle switch, the socket uses the DC-005 type, and the LED lampshade is modified from a discarded plastic chip box. Then fix the circuit board, socket, switch and battery in the mouse with AB glue.

The parameters of the components in the circuit are shown in the attached table. The circuit printed board diagram is shown in Figure 2.