This is another LED lamp from China a firm called Hoya, these people make nice lamps and also good designs of the plastic enclosure. Here by a clever enclosure design it is both a emergency mains bulb and Torch/Flashlight. The price is low and they use a small sealed lead-acid battery worth 4.5 V and [...]
Archive of posts tagged Schoodles
Mains Powered China Emergency Bulb
A typical Mains Powered China Lamp. On power down, LED light turns on for around 1/2 hr. Gets damaged on lightning activity and wide (uS not nS) transients above 300V. Drawing may have error. From Schoodles
Torch or Flashlight Circuit Improvements
I fixed a China Torch with New LEDs and a Diode, it failed probably on a drop shock, the battery wire cut … then when put on charge Few LEDs went bad, as battery was absent in ckt. design review – 1.5uF voltage rating can increase like 440V AC. A current source with low dropout [...]
LED Lamp – Simple Bed-Lamp Circuit
LED Night lamp, Clock Lamp to see time at night. It is a Green Lamp just 50mA, but its Blue in Color. From Schoodles This can be a first LED Lighting project anybody can do. Just twist wire, use insulation tape. Get a Nice Mains adapter that will provide 6V DC. 5V also will do. [...]
Mains Adapter 230V AC 50 Hz to Rectified DC
Mains Adapter Converts 230V AC 50 Hz to Rectified DC which replaces a Battery Pack. It was also called Battery Eliminator by older generations as it was used to save Battery Cost in AM Radios. A Doodle in a Schematic Diagarm or a Circuit with Doodles is known as Schoodle. Here are some Drawings of [...]
Ni-Cd and Li-ion Battery charger Generic
This is a Generic charger that is made by many brands, the circuit is an approximation of all. Some improvements suggested. Some brands in europe and usa also use this circuit. This works well, but may not be in the best interest of battery life. The cost of the charger needs to be low. So [...]
LED Flashlight made out of a China Lamp
LED Flashlight made out of a China Lamp that was busted on a High voltage surge during a Thunderstorm. From Schoodles I got many LED lamps, mainly from china. The Chinese Entrepreneurs are Creative and Adventurous. There is a problem though, the quality, reliability and safety factors are not so good. These are so for [...]
Emergency Light with Fluorescent Tubes
Emergency Light for Portable Use. Note Charger and Battery not Shown. Design from Ludens.cl 12 Volt fluorescent lamp drivers: Three schematics of 12 V drivers for 2, 8 and 20 Watt, plus a lot of explanations about fluorescent tubes. Use the drivers for camping, emergency, boating, etc. From Schoodles Improper Design of Magnetics or Testing [...]
Charger for Portable Devices like iPod
This is a simple charger you can build for devices like iPod or iPhone. It works for ipod touch. It can be modified for any device. This may need no modification for devices that are charged using PC USB port. This is a Schematic Doodle called Schoodle. Use it for Learning and understanding. Build and [...]
One Watt Mains LED Lamp or Tubelight
Lots if Light on One Watt, yes this works, but should be built by those experienced in High Voltage usage and Knowledge of insulation techniques. This has to be encapsulated in a insulated fire retardant plastic enclosure. You can change the values around what is indicated to experiment with types of White LED available. This [...]
Powered USB Hub Help PC Interface
I got a strange problem as i added more and more peripherals, the pc gave odd messages, “i cannot detect what you are doing” and things like that. I almost flipped trying to locate the culprit. The problem was not in any peripheral but in the USB port powering the system itself. The SMPS was [...]
