DIY Solar Lights: Smart Outdoor Lighting Solution

Continuation of the previous post: DIY Solar Lights: Enhanced Motion Sensing & Efficiency

Currently, the setup includes solar light control with a few hours of timed consistent lighting and an external SR501 PIR motion sensor module (modified from the scheme 2 SR501 module, installed 4 meters above the ground with an effective sensing distance of 6-8 meters, maintaining good sensitivity).

In the first half of the night, the light stays on consistently and is motion-sensitive, while in the second half, it operates on motion sensing only. This arrangement helps prevent unnecessary battery drain.

You can find the datasheet for the EC340EGB timing IC online. The timer has a wide range but outputs a low level, which isn't suitable for directly driving large LED lights. At a voltage of 3V, it outputs 20 mA; at 4V, it outputs 45 mA; and at 5V, it outputs 73 mA. Therefore, a workaround is needed.

The timing IC's triggering filter capacitor circuit has been modified.

Board size: 37.4mm x 20.7mm.

When the solar panel voltage drops below 0.6V, the timer is triggered, causing the LED light to turn on. Once the timing is complete, the LED light turns off, and no additional triggers can occur in between. This setup is optimal for outdoor lighting but may illuminate too late for indoor use.

Components:

U1: TP4056 charging management chip (5V to 9V input voltage range, suitable for 5V to 7V solar panels, with a charging cut-off voltage of 4.10V to 4.17V). Available on Taobao for a low price.

U2: EC340EGB timing IC (maximum working voltage of 5V, wide timing range, low-level timing output). Available on Taobao for 0.73 RMB each.

U3, U4, U5, U6: SS8050 SMD transistors.

U7: 7135 constant current IC. Options available on Taobao include 120mA, 150mA, 180mA, 200mA, 250mA, 300mA, 350mA, and 380mA.

R400, C1, C2, and C3 use 1206 packages (alternatively, 0805 packages), while other resistors use 0603 packages.

RT is the timing oscillator resistor, and its value multiplied by 512 gives the total output time (in seconds).

Other parameters are specified on the main board.

If bypassing the 7135 constant current IC, it is recommended that the LED light's working current does not exceed 1000 mA.