Diy Christmas lights - Revision history

Mol: /* Photodiode and transistors */

2022-11-13T18:05:24Z

Photodiode and transistors

← Older revision		Revision as of 21:05, 13 November 2022
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	[[File:Photodiode.svg\|thumb\|A simple photodiode circuit by EvilMadScientist]]		[[File:Photodiode.svg\|thumb\|A simple photodiode circuit by EvilMadScientist]]

			References
	* https://www.evilmadscientist.com/2007/a-simple-and-cheap-dark-detecting-led-circuit/		* https://www.evilmadscientist.com/2007/a-simple-and-cheap-dark-detecting-led-circuit/
	* CdS (“LDR”) phototransistor circuits		* CdS (“LDR”) phototransistor circuits

	== result ==		== result ==

Mol: /* Photodiode and transistors */

2022-11-13T18:05:05Z

Photodiode and transistors

← Older revision		Revision as of 21:05, 13 November 2022
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	https://www.evilmadscientist.com/2007/a-simple-and-cheap-dark-detecting-led-circuit/		* https://www.evilmadscientist.com/2007/a-simple-and-cheap-dark-detecting-led-circuit/
			* CdS (“LDR”) phototransistor circuits

	== result ==		== result ==

Mol: /* Theory */

2022-11-13T18:02:57Z

Theory

← Older revision		Revision as of 21:02, 13 November 2022
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	Use leds in series, as parallel leds might light on uneven brightness.		Use leds in series, as parallel leds might light on uneven brightness.

			Usually the longer led is the + lead.

	=== LEDs and wiring ===		=== LEDs and wiring ===

Mol: /* Photodiode and transistors */

2022-11-13T18:00:44Z

Photodiode and transistors

← Older revision		Revision as of 21:00, 13 November 2022
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	* and a 1 k resistor.		* and a 1 k resistor.

			[[File:Photodiode.svg\|thumb\|A simple photodiode circuit by EvilMadScientist]]

Mol: /* Photodiode and transistors */

2022-11-13T17:59:47Z

Photodiode and transistors

← Older revision		Revision as of 20:59, 13 November 2022
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	=== Photodiode and transistors ===		=== Photodiode and transistors ===

			We can use a photodiode and transistor to turn a led on. The example given by EviMadScientist uses
			* a battery,
			* an LTR-4206E phototransistor (in a black package: blocks visible light; sensitive to IR)
			* a 2N3904 transistor,
			* and a 1 k resistor.




			https://www.evilmadscientist.com/2007/a-simple-and-cheap-dark-detecting-led-circuit/

	== result ==		== result ==

Mol: /* LEDs and wiring */

2022-11-13T17:51:50Z

LEDs and wiring

← Older revision		Revision as of 20:51, 13 November 2022
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	If we use simple AA batteries, we will need <math>14\times 1.5= 21 V</math> or <math>16\times1.5 = 24 V</math>. Quite many. . .		If we use simple AA batteries, we will need <math>14\times 1.5= 21 V</math> or <math>16\times1.5 = 24 V</math>. Quite many. . .

	However, if we wire them alternately, it makes <math>3\times2.9V=8.7V</math> and <math>4\times2.9V=11.6V</math> for blue leds and <math>3\times3.3V=9,9V</math> and <math>4\times3.3V=13,2V</math> the white leds.		However, if we wire them alternately, it makes <math>3\times2.9V=8.7V</math> and <math>4\times2.9V=11.6V</math> for blue leds and <math>3\times3.3V=9,9V</math> and <math>4\times3.3V=13,2V</math> the white leds. Thus, we need only six (6) or eight (8) batteries; or 7 and 9 in the case of white leds.

	=== Photodiode and transistors ===		=== Photodiode and transistors ===

	== result ==		== result ==

Mol: /* Theory */

2022-11-13T17:50:11Z

Theory

← Older revision		Revision as of 20:50, 13 November 2022
Line 16:		Line 16:
	If we use simple AA batteries, we will need <math>14\times 1.5= 21 V</math> or <math>16\times1.5 = 24 V</math>. Quite many. . .		If we use simple AA batteries, we will need <math>14\times 1.5= 21 V</math> or <math>16\times1.5 = 24 V</math>. Quite many. . .

	However, if we wire them alternately, it makes <math>3\times2.9V=8.7V</math> and <math>4\times2.9V=11.6V</math> for blue ~~led~~ and <math>3\times3.3V=9,9V</math> and <math>4\times3.3V=13,2V</math> the white leds.		However, if we wire them alternately, it makes <math>3\times2.9V=8.7V</math> and <math>4\times2.9V=11.6V</math> for blue leds and <math>3\times3.3V=9,9V</math> and <math>4\times3.3V=13,2V</math> the white leds.

	=== Photodiode and transistors ===		=== Photodiode and transistors ===

	== result ==		== result ==

Mol: /* LEDs and wiring */

2022-11-13T17:48:49Z

LEDs and wiring

← Older revision		Revision as of 20:48, 13 November 2022
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	* White: 3.3 V		* White: 3.3 V

	Seven blue leds makes <math>2.9~~\times7~~=20.3 V</math>, and white blue leds drops the voltage by <math>3.~~3\times7~~=23.1 V</math>.		Seven blue leds makes <math>7\times 2.9 V =20.3 V</math>, and white blue leds drops the voltage by <math>7\times 3.3V=23.1 V</math>.
			If we use simple AA batteries, we will need <math>14\times 1.5= 21 V</math> or <math>16\times1.5 = 24 V</math>. Quite many. . .
	If we use simple AA batteries, we will need <math>14\times 1.5= 21 V</math> or <math>16\times1.5 = 24 V</math>. Quite many. . .

			However, if we wire them alternately, it makes <math>3\times2.9V=8.7V</math> and <math>4\times2.9V=11.6V</math> for blue led and <math>3\times3.3V=9,9V</math> and <math>4\times3.3V=13,2V</math> the white leds.

	=== Photodiode and transistors ===		=== Photodiode and transistors ===

	== result ==		== result ==

Mol: /* Theory */

2022-11-13T17:44:46Z

Theory

← Older revision		Revision as of 20:44, 13 November 2022
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	== Theory ==		== Theory ==

			Use leds in series, as parallel leds might light on uneven brightness.

	=== LEDs and wiring ===		=== LEDs and wiring ===

			* Red and yellow led: 2 V
			* Green and blue led: 2.9 V
			* White: 3.3 V

			Seven blue leds makes <math>2.9\times7=20.3 V</math>, and white blue leds drops the voltage by <math>3.3\times7=23.1 V</math>.

			If we use simple AA batteries, we will need <math>14\times 1.5= 21 V</math> or <math>16\times1.5 = 24 V</math>. Quite many. . .


	=== Photodiode and transistors ===		=== Photodiode and transistors ===

	== result ==		== result ==

Mol: Created page with "== Introduction == Make a simple battery powered Christmas light with seven (7) leds. == Theory == === LEDs and wiring === === Photodiode and transistors === == result =="

2022-11-13T17:40:09Z

Created page with "== Introduction == Make a simple battery powered Christmas light with seven (7) leds. == Theory == === LEDs and wiring === === Photodiode and transistors === == result =="

New page

== Introduction ==

Make a simple battery powered Christmas light with seven (7) leds.

== Theory ==

=== LEDs and wiring ===

=== Photodiode and transistors ===

== result ==