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29 Aug 2014

obr1576_1

Pulse-controlled dimmers of lighting – Finder series 15 offer an elegant solution of lighting dimming controlled by a single switch.

Possibility to control level of lighting is beneficial at least from two reasons – saving of energy and naturally – we don´t need always a full intensity of lighting. At watching of media-projector presentation, TV, illumination of corridors, … it´s often desirable only to reach only a minimum level of illumination (but not a total darkness). Light dimmers are for a long period used for these purposes, usually based on a phase regulation.

Solution from company Finder is exceptional in a fact, that it´s usable with almost every light source – for example incandescent bulbs, 230V halogen bulbs powered by a toroidal or EI transformer, dimmable CFL lamps, as well as LED bulbs. The essence of Finder 15 series dimmers versatility is in the possibility to choose a method of a phase regulation – on the beginning of the sinusoid, or on its end (leading/ trailing edge – the difference is illustrated on the attached picture). The first method is generally suitable for electronic transformers for halogen bulbs and LEDs, the second method is better for classic transformers for low voltage bulbs, for 230V CFL and for 230V LED lamps.

As it uses to be, control of such dimmers is maximally simple – by a short push of a control button (switch) the relay (output) will switch on or switch-off. By a longer holding the button presses, we can change the light intensity from minimum to maximum and vice versa. Finder 15 series dimmers also enable to work in a mode with a switched on memory (after a repeated switch on, the last used level of intensity will be set) or without a memory (after switching on, the maximum intensity will be set). An above standard benefit is a possibility to adjust a minimum light intensity by a potentiometer, what´s important mainly at electronic transformers to avoid a possible blinking at very low intensities and it´s also at classic incandescent bulbs, as their efficiency drops down rapidly at very low intensities (duty cycles).  

All 3 produced types are available directly from our stock:
15.51.8.230.0404 – assembly to installation boxes, linear dimming (also available types with dimming in 10 incremental steps)
15.81.8.230.0500 – assembly to boxes or on a panel, linear dimming
15.91.8.230.0000 – DIN rail assembly, linear dimming

Available are various versions, detailed information and a comprehensive table about possibilities of usage of particular types will give you the Finder 15 datasheet.

One impulse is able to set intensity of luminance - [Link]

25 Aug 2014

FDXBRBHHZ2IW5T8

Here’s a proximity-sensing LEDs project by Will_W_76. He writes a complete step-by-step instructions:

So how does this all work? What makes it proximity-sensing? Remember in the explanation above that the photo-transistor acts like a switch. So when the photo-transistor is off, no current is flowing across it to our blue LED and the LED is off as well. Now look at the other side of our circuit. That’s where the IR LED is connected, and it is connected such that it is always on and emitting 880nm infrared waves. Remember that I also mentioned the photo-transistor is set to respond best to wavelengths of 880nm? That’s how the proximity-sensing works! When an object (such as your hand) goes over this little “cluster”, IR light of 880nm is emitted from the IR LED. This light reflects off of your hand and back to the circuit. When the photo-transistor picks it up, it turns on allowing current to flow through from the source to our blue LED lighting it up!

[via]

Proximity sensing LEDs - [Link]

20 Aug 2014

buitenlicht2

by  Deddieslab :

I have a couple of front door LED lights which I would like to switch on automatically during the evening/night. The two conventional methods that are commonly available had their disadvantages:

A timer switch is the easiest and cheapest solution, but doesn’t take into account day light savings. Besides that, in Einhoven, the Netherlands where I live in december the sun sets around 16:30 while in June it doesn’t get dark before 22:00. A simple timer doesn’t take that into account either.

Since you only want the lights on when it gets dark, instead of time you can also use a light sensor to distinguish day and night. You have these front door lights that have this built in. The problem that I had with these devices is that they start bouncing (‘flickering’) around sunset/sunrise. They constantly turn on/off which causes damage to the LED lights I was using. This cost me already several expensive led lights.

Frontdoor light switch based on local sunset/sunrise - [Link]

16 Aug 2014

LED_clock

by embedded-lab.com:

This Instructable describes building of a fun and very simple LED clock using Arduino that displays the time to the nearest half hour using LEDs.

Arduino LED clock - [Link]


12 Aug 2014

stroboscope_panel1-600x450

ReturnZero published a stroboscope build:

At its heart, a stroboscope is just a rectangular wave generator hooked up to a light source. I wanted a few extra features to make it nice to use:
Ability to set flash rate by either frequency or RPM
Set duty cycle of output without affecting flash rate
LCD display

- 2×16 for displaying RPM, frequency and duty (one per line, so one will be hidden at any time)
Rotary encoder (with button) for main interface

- When button is not pressed, knob will increase/decrease the value of the selected digit
- When button is pressed, rotating knob will scroll through display digits
Buttons for quickly halfing/doubling thirding/trebling the flash rate

- This is useful for checking that you haven’t hit on a multiple of the rotation rate
Nice beefy output stage for switch big sets of LEDs

[via]

DIY stroboscope - [Link]

12 Aug 2014

7seg-front.preview1

Spacewrench over at Dorkbotpdx writes:

I had some spare 4-digit 7-segment LED displays and some AT90USB82s, and I’d always intended to do something with them. This was probably the easiest thing! It’s just the AT90 driving the display, with a(t least) 4 wires controlling it: Vcc, GND, MOSI and SCK. (I haven’t written the code yet, but my plan is to make the display accepts characters via SPI and then spends the rest of the time displaying them).
The board has footprints for a 16MHz crystal and USB connector, so you could make it a USB-enabled 7-segment display as well. I stuffed those parts on my test board, but I’m not sure whether the USB actually works. You can power the display from USB, at least, although the video shows it being powered over SPI (which is the same connection I use to flash code).

[via]

Standalone SPI 7-segment display - [Link]

8 Aug 2014

FT1094_bell-500x259

by Boris Landoni @ open-electronics.org:

Since when white light emitting high brightness LED are available, the handover from traditional lighting bulbs to the solid-state lighting has become irreversible: LEDs have an efficiency (expressed in lumens/watt) higher than that of almost all the traditional lamps (except, at the moment, the large sodium vapor lamps used for street lighting, unusable in closed environments for the high power required and the chromatic aberration they produce) at a cost that is today less prohibitive than it was a few year ago. They are indeed very sturdy and have a very acceptable ratio of luminous flux and size.

The perfect Remote, Programmable, Controller for interactive LED strips - [Link]

5 Aug 2014

DI5456sch

by BABU TA @ edn.com:

This flasher/beacon circuit can be employed as a distress signal on highways, a direction pointer for parking lots, hospitals, and hotels, etc. The circuit uses a power LED, and provides more light than a typical incandescent lamp flasher. Use of a 6V or 12V SLA lantern battery makes the circuit portable.

HB-LED flashing beacon repurposes switching regulator - [Link]

4 Aug 2014

2014-07-12-16.25.19-1024x768

by dreded @ dredx.com:

In my home I have a fairly long hallway that has light switches at either end but 99% of the time we enter the hallway from the middle where there is no switch. So I decided I needed to do something about this as walking down a dark hallway all the time was annoying.

I have seen a fair number of people use an arduino or even a standalone ATTiny85 with a El cheapo HC-SR501 which can be found on ebay for about $1.25 each and I find these things work fantastic, they have an excellent range and detection spread.

Motion activated lighting without a Micro-Controller - [Link]

4 Aug 2014

apps-600x344

An application note from Texas Instruments, white LED driver with digital and PWM brightness control (PDF!):

With a 40-V rated integrated switch FET, the TPS61160/1 is a boost converter that drives LEDs in series. The boost converter runs at 600kHz fixed switching frequency to reduce output ripple, improve conversion efficiency, and allows for the use of small external components.
The default white LED current is set with the external sensor resistor Rset, and the feedback voltage is regulated to 200mV, as shown in the typical application. During the operation, the LED current can be controlled using the 1-wire digital interface ( Easyscale™ protocol) through the CTRL pin.

[via]

App note: White LED driver with digital and PWM brightness control - [Link]



 
 
 

 

 

 

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