Transformer step-down LED energy-saving lamp production

Recently, I have been thinking about using a simple circuit with a transformer to step down the voltage to make a high-power LED energy-saving lamp, with an efficiency of about 80%. The schematic diagram is shown in Figure 1. The circuit board is arranged in Figure 2, and the electronic components are shown in Figure 3 (omitted). It is clear at a glance.

The author uses a small 10W transformer at home to make a high-power LED energy-saving lamp. Although the price is more expensive than a capacitor, it saves power consumption and electricity bills because the circuit is simple and saves money. The lamp base designed and made by the author is made of glass fiber board. During processing, holes are punched at the corresponding positions. The rectifier part, resistors, and capacitors use 1.3mm hollow copper rivets, and the lamp beads do not need rivets. The sample of the circuit board is basically welded. As shown in Figure 4 (omitted).

After the lamp is welded and installed as shown in the schematic diagram and photos, it should be checked and verified before powering on. If it is correct, it will generally work normally and emit dazzling white light.

After power on, the author measured that the series current of each loop is 155mA, the total voltage of 5 lamp beads is 14V, the voltage on the 3.6Ω resistor is 0.55V, the power consumption of the lamp beads is 2×2.17W, the resistor is 2×0.083W, and the total is about 4.6W. The efficiency of a general small transformer is 90%. The total power consumption of this lamp is 5W 25.8W. The power consumption of the luminous lamp beads exceeds 85%, which is a relatively efficient high-power energy-saving lamp.

Resistors R1 and R2 play a balancing role for the two series-connected lamp beads. For example, when the lamp beads are short-circuited and damaged, the fuse (0.5A) plays a role in protecting the transformer. Generally, it cannot be cancelled. The electrolytic capacitor C1 plays a role in raising the voltage a little to maintain the efficiency of the rectifier circuit.

The lamp that the author has made for the experiment is now complete. After actual observation, this lamp is about equal to the brightness of a 15W fluorescent lamp, but it consumes much less power than a fluorescent lamp. It is a green, environmentally friendly and energy-saving lamp, suitable for DIY imitation production by electronics enthusiasts.

In addition, the general drawing is 12 high-power lamp beads, and the efficiency of the LED energy-saving lamp produced is also above 80%. The total brightness is approximately equal to the brightness of a 20W fluorescent lamp. The experimental parameters are that the voltage on the 6 lamp beads is 17V, the voltage on the resistor is 0.65V, and the series loop current is 180mA. The power consumption on the lamp beads is 2×3W. The power consumption on the resistor is 2×0.178W. The total power consumption is about 6.5W, plus the transformer loss. The total power consumption is about 7.2W. It is a high-efficiency lamp, and the total brightness of the lamp is approximately equal to the brightness of a 20W fluorescent lamp. The disadvantage is that the transformer is relatively bulky and expensive.

So far, the author has finished introducing the design and production of high-power LED energy-saving lamps with simple circuits.