What is a Light Activated Silicon Controlled Rectifier_ (LASCR)
-
Upload
donika-markande -
Category
Documents
-
view
16 -
download
8
description
Transcript of What is a Light Activated Silicon Controlled Rectifier_ (LASCR)
-
2/28/2014 What is a Light Activated Silicon Controlled Rectifier? (LASCR)
http://www.bristolwatch.com/ele/lascr.htm 1/8
What is a Light Activated Silicon Controlled Rectifier? (LASCR)
by Lewis Loflin
A light activated silicon controlled rectifier (LASCR) is a silicon controlled rectifier (thyristor) that conducts when the gate isexposed to light. The gate still operates as a normal gate in a SCR, but is in many cases left disconnected. LASCR is aunidirectional device that conducts current in only direction. The basic LASCR circuit is illustrated above. Like all SCRs and
triacs one must use A.C. or pulsating D.C. for proper operation. Also see Basic SCRs/Triacs.
Circuit Board Assemblythuse.net/Enquire_Now
Pioneer Manufacturer & Supplier Of Printed Circuit Boards Assembly.
-
2/28/2014 What is a Light Activated Silicon Controlled Rectifier? (LASCR)
http://www.bristolwatch.com/ele/lascr.htm 2/8
While the light source to activate a LASCR can be a simple flashlight or light bulb, the source is often a light emitting diode or
LED as illustrated above.
-
2/28/2014 What is a Light Activated Silicon Controlled Rectifier? (LASCR)
http://www.bristolwatch.com/ele/lascr.htm 3/8
Illustrated above a LED and LASCR in the same package. This often six-pin device is called an opto-coupler. These devicesprovide electrical isolation between the input and output circuits. In the case of the of the H11Cx series illustrated above this willprovide isolation of up to 5300 volts RMS. Also H11C6 SCR opto-Coupler (PDF file)
In the above circuit we are using a H11C6 opto-coupler to directly drive a 25-watt light bulb. The SCR section of the opto-coupler is rated at 400 volts at 300 milliamps. (mA) Note that being a unidirectional device, the SCR will provide only half-waverectification and the bulb will only be about half as bright. The input can be controlled from 5-volt computer logic.
-
2/28/2014 What is a Light Activated Silicon Controlled Rectifier? (LASCR)
http://www.bristolwatch.com/ele/lascr.htm 4/8
In the above circuit we are using as SCR output (H11C6) to switch off a triac. The output of the H11C6 is a light activatedsilicon controlled rectifier or LASCR.
-
2/28/2014 What is a Light Activated Silicon Controlled Rectifier? (LASCR)
http://www.bristolwatch.com/ele/lascr.htm 5/8
Finally in the above circuit we are using a H11C6 through a diode bridge to switch on a triac. This circuit operates as full waveand delivers max power to the load.
About me Bristol VA/TN E-Mail Hobby Electronics Arduino Microcontroller
-
2/28/2014 What is a Light Activated Silicon Controlled Rectifier? (LASCR)
http://www.bristolwatch.com/ele/lascr.htm 6/8
Added July 31, 2011
Using Hall Effect Switches
Using Ratiometric Hall Effect Sensors
Using Hall Effect Sensors with the Arduino-ATMEGA168
Connecting the Arduino to the TMP37 Centigrade Temperature Sensor
How to connect batteries in Series/Parallel
12AV6 Vacuum Tube AM Radio
Coils for Highly Selective Crystal Radio
Adding a Push-Pull Output Stage to a LM386 Audio Amplifier
-
2/28/2014 What is a Light Activated Silicon Controlled Rectifier? (LASCR)
http://www.bristolwatch.com/ele/lascr.htm 7/8
Read this safety warning and Disclaimer
Tutorial: Transistor-Zener Diode Regulator Circuits
Tricks and Tips for the LM78XX Series Voltage Regulators
Bi-Polar Power Supplies
Build a Thermocouple Amplifier
Build a Potato battery
Build an Adjustable 0-34 volt power supply with the LM317
Testing a Diac
Basic Triacs and SCRs
Solid State AC Relays with Triacs
Light Activated Silicon Controlled Rectifier (LASCR)
Basic Transistor Driver Circuits for Micro-Controllers
Opto-Isolated Transistor Drivers for Micro-Controllers
Build a H-Bridge Motor Control with Power MOSFETS
Series/Parallel batteries
Using a CdS Photocells
Voltage Comparator Information And Circuits
Resistive Humidity Sensors
Reed Switches
Basic Power Transformers
Power Supply Rectification
-
2/28/2014 What is a Light Activated Silicon Controlled Rectifier? (LASCR)
http://www.bristolwatch.com/ele/lascr.htm 8/8
Diodes and Rectifiers
Web site Copyright Lewis Loflin, All rights reserved. If using this material on another site, please provide a link back to my site.