Solar Light For A Portable Toilet Using PIR sensor and LM317


Circuit for a solar-powered, self-contained light for portable toilet illumination applications.


Solar Light Circuit For a Portable Toilet

Author: T.K Hareendran

Portable toilets, which are self-contained and can be installed almost anywhere, are more costly than permanent outdoor toilets but offer numerous key advantages. Today, portable toilets are often encountered in outdoor settings such as construction sites, farms, campgrounds, and even streets. Solar energy is well suited for situations where illumination is needed in portable toilets that are situated distant from the main power grid or if the installation is planned to be temporary.

The figure shown above is a circuit for a solar-powered, self-contained light for portable toilet illumination applications. The self-contained solar light consists of a solar charger, rechargeable battery pack, white LED light source, and PIR occupancy sensor. The occupancy sensor (motion sensor) activates the light source, and when the booth has been vacated (or if no legitimate motion is detected), the lights turns off to save battery power.

Working of the circuit:

The above figure depicts the circuit diagram of the solar light for a portable toilet. It consists of a 9V, 450mA solar panel, a voltage regulator LM317 (IC1), a PIR sensor, a MOSFET BS170 (T1), a 1W white LED (LED1), and a few more components.

It is possible to divide the circuit into two sections: the charger and the sensor and control system. The 9V, 450mA-rated polycrystalline solar panel provides power, is connected to CON1, and charges the 4.8V, 1800mAh battery pack, BATT.1, through the IC1-based constant-current charger. The 6.8-ohm resistor (R1) restricts the charging current to around 180mA, or one-tenth the pace of the battery.

Parts Required:

IC1 - LM317 With Heatsink
T1 - Bs170 MOSFET
LED1 - 1Watt, 3.6V
Resistors (All 1/4 watt unless specified):
R1 - 6.8 Ohm
R2 - 4.7 ohm, 1 Watt
R3 - 100 ohm
S1 - SPDT Switch
CON1 - Two pin connector terminal
CON2 - 3 pin connector
CON3 - Two pin connector for LED1
BATT1 - 2 pin connector terminal
- 4.8v. 1800mAh Ni MH Battery
- 9V, 450mA Solar Panel
- PIR Sensor
- Appropriate Enclosure

The sensing and control circuitry is based on a PIR motion detector module (Fig. 3), which is linked to CON2. When a legitimate motion is detected, the output of the PIR sensor rises to around 3.3V and the medium-power MOSFET BS170 turns on the light source LED1 (3.6V, 1W white LED) for a limited duration. The 1W, 4.7-ohm resistor R2 restricts the white LED's operational current.

Construction And Working:

Enclose the PCB in an appropriate little box that may be installed in the toilet. Connect the fully-charged battery pack BATT.1 to the circuit and turn on S1 after constructing the PCB board. The PIR motion sensor detector takes around 60 seconds for initialization (or even up to three minutes). After that, it enters standby mode, where it is available for detection.

You may turn the PIR sensor's delay potentiometer clockwise to extend the time delay from three seconds to up to 300 seconds. Similarly, moving the sensitivity pot counterclockwise on a PIR sensor extends its detection range from three to six metres. In some PIR sensor potmeters, the LDR socket is unavailable.

The solar panel (which is not installed inside the enclosure) may be positioned in a suitable location. The ideal way to connect the BATT.1 battery pack to the circuit is using two flexible, well-insulated multi-strand wires. Then, a heat sink should be fitted to the integrated circuit LM317. Install the completed PCB in a tiny plastic box with connection holes drilled for the solar panel, S1 switch, LED1, and PIR motion sensor.

PIR Sensor

Source: EFY

Laptop Repair Made Easy
Laptop Repair Made Easy
Amazon Affiliate Disclaimer:The owner of this website( is a participant in the Amazon India Associates Programme, an affiliate advertising programme designed to provide a means for sites to earn advertising fees by advertising and linking to

Alarm circuit,6,Audio Amplifier Circuit,1,Audio Circuit,2,charger circuit,4,connection details,1,Controller circuit,7,Emergency Light Circuit,2,Indicator Circuit,12,Inverter Circuit,1,LED Circuit,5,Multivibrator Circuits,1,Power supply,1,Rectifier Circuit,1,timer circuit,1,
Simple Electronic Circuits: Solar Light For A Portable Toilet Using PIR sensor and LM317
Solar Light For A Portable Toilet Using PIR sensor and LM317
Circuit for a solar-powered, self-contained light for portable toilet illumination applications.
Simple Electronic Circuits
Loaded All Posts Not found any posts VIEW ALL Readmore Reply Cancel reply Delete By Home PAGES POSTS View All RECOMMENDED FOR YOU LABEL ARCHIVE SEARCH ALL POSTS Not found any post match with your request Back Home Sunday Monday Tuesday Wednesday Thursday Friday Saturday Sun Mon Tue Wed Thu Fri Sat January February March April May June July August September October November December Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec just now 1 minute ago $$1$$ minutes ago 1 hour ago $$1$$ hours ago Yesterday $$1$$ days ago $$1$$ weeks ago more than 5 weeks ago Followers Follow THIS PREMIUM CONTENT IS LOCKED STEP 1: Share to a social network STEP 2: Click the link on your social network Copy All Code Select All Code All codes were copied to your clipboard Can not copy the codes / texts, please press [CTRL]+[C] (or CMD+C with Mac) to copy Table of Content