Hobby Circuits designed by Dave Johnson

Last Updated on: Sunday, December 24, 2017 07:30 AM


Text & Graphics Copyright © David A. Johnson, PE  --  ALL Rights Reserved.
LINKING to Dave's circuits is permitted but COPYING CONTENT to your WEB SITE server IS NOT!

Laser Light Detyector-10Mhz to 20Mhz

LED/Laser Light Output Intensity Meter

Light Detector

Light Detector with High Ambient Light Immunity

Light Monitor Circuit

Light Pulse Receiver + Post Amp

Light Receiver 30Khz Amp

Light Receiver Front-End Circuit

Light Receiver Works from 1Khz to Over 70Mhz

Light Receiver-10MHz to 20MHz

Light to Frequency Converter

Light/Dark 12V Switch

Line-Powered Xenon Flash Transmitter

Low Power 40KHz Light Detector

Low Power Amp Monitors Light

Low-power optical interrupter

Micro Power 40Khz Burst Laser Diode Driver

Modified Cheap Solar LED Path Light

Modified LED Night Light

Modulated Light Monitor #1

Modulated light receiver circuit

Modulated Light Receiver uses a Single IC

Monitor Clear Fluids

Night Light from White LED

One-Watt White LED Night Light

Operation of Cascode Light Receivers

Optical Fiber Receiver-5Mhz Broad Band

Optical Filter using Color Film Negative

Optical Interrupter Draws Microamps

Optical RFID Test Circuit

Photo Transistor interface Circuit

Photovoltaic Solar Panels-Ideal Blocking Diode Circuit

PV Solar Cell Test Fixture

PV Solar Panels-Ideal Blocking Diode Circuit

Reduce voltage to Photovoltaic Solar Panel with Ideal Diode

Remote Extender Circuit

RFID Test Circuit

Safety Light

Salvaged Broken Solar Cells

Shop Safety Light

Simple Circuit for White LED Night Light

Single IC forms Senesitive Modulated Light Receiver

Slotted Opto-Sensor used in Honeybee Counter

Slotted-Type Optical Interrupter Draws Microamps

Snow Depth Alarm

Solar Cell Test Fixture

Solar Insolation Monitor

Solar Lithium Ion Battery Charger using LT1131

Solar Path Light Improvement

Solar Powered Cell Phone Charger

Solar Powered Flood Light using NiMH
Cells

Solar Powered Infrared 1W Security Camera Illuminator

Solar Powered Lithium Ion Battery Charger

Solar PV Cell Test Fixture

Solar-Powered Pump Motor Controller

Time to Dust

Transmitter for Line Powered Xenon Flash

TV-VCR Light Source 40Khz Repeater

Ultra Low Power Detects Clear Fluid

Use Color Film Negative to Make an Optical Filter

Variable Isolated AC Voltage Spans 0VAC to 280Vac

Water Pump controlled by Solar Power

Xenon Flash Receiver-Pg2

Xenon Lamp Flash Detector Amplifier

10Mhz to 20Mhz Light Receiver

12 Volt Lite/Dark Lamp Switch

12v Light/Dark Lamp Switch

12v Touch Switch Exciter Circuit

12v-24v AC & DC Day/Night Switch

1Khz to Over 70Mhz Light Receiver

1us Light Pulse Receiver

1uS Light Pulse Receiver + Post Amp

1W White LED Night Light

20Mhz VCSEL 3mw Laser Test Circuit

24 Volt Day Night Switch

24v NiMH
Battery Charger using a 12v Solar Panel 

2Mhz Broad Band Optical Fiber Receiver

30Khz Light Receiver Amp

3mw Laser Test-20Mhz VCSEL

40Khz Burst Laser Diode Driver

40Khz Laser Burst Detector

40Khz Light Detector with High Ambient Light Immunity

40KHz Light Receiver Front-End Circuit

40KHz Modulated Light Detector

40khz TV-VCR Light Source Repeater

50Mhz Broad Band Optical Fiber Receiver Version A

5Mhz Broad Band  Optical Fiber Receiver

6V to 24V DC Day/Night Switch

8-Solar Cell Lithium Ion Battery Charger Version 2

AIR Transparency Monitor-Pg2

Ambient Light Dectector with Compensation

Amplifier for a Xenon Lamp Flash Detector

Broad Band 2Mhz Optical Fiber Receiver

Broad Band 50Mhz Optical Fiber Receiver Version A

Broken Solar Panels

Cascode Light Receiver Circuit

Cell Phone Solar Powered Charger

Clear Fluid Detector #2

Color Film Makes Optical Filter

Convert Solar Powered Light to Flasher

Dark Activated 12v Power Supply Switch

Day/Night Switch-24vAC Powered

Detect Clear Fluid

Detect Short Xenon Lamp Flashes

Detects Xenon Lamp Flash

Eight-Solar Cell Lithium Ion Battery Charger Version 3

FET Input High Speed Light Detector

Fully Isolated 50/60hz Sync Generator

High Ambient Light Immunity Light Detector

High Speed Light Detector from FET Input

High-speed 75MHz light receiver

Honeybee Counter

Ideal Blocking Diode Circuit for Photovoltaic Solar Panels

Ideal Diode for PV Panels

Ideal Diode Function

Improve Response Time of a Photo Transistor Circuit

Improved Solar LED Spot Light

Improved Solar Path Light

Indicates when it is Time to Dust

Indicates when it is Time to Dust

Infrared Remote Extender Circuit

It's Time to Dust Indicator