RPi Tutorial EGHS:12V relay driver - Revision history

Juraj: /* The Hardware */

2012-07-31T22:35:13Z

‎The Hardware

Juraj: /* The Hardware */

2012-07-31T21:46:46Z

‎The Hardware

Juraj: /* The Hardware */

2012-07-31T21:41:45Z

‎The Hardware

Juraj: /* The Hardware */

2012-07-31T21:40:49Z

‎The Hardware

Juraj: Created page with "{{Template:RPi Tutorials}} ''This page is part of a work in progress.'' ==Warnings== While most of these circuits may interface directly to the RPi, the use of a buffered int..."

2012-07-31T21:38:44Z

Created page with "{{Template:RPi Tutorials}} ''This page is part of a work in progress.'' ==Warnings== While most of these circuits may interface directly to the RPi, the use of a buffered int..."

New page

{{Template:RPi Tutorials}}

''This page is part of a work in progress.''

==Warnings==
While most of these circuits may interface directly to the RPi, the use of a buffered interface (such as the one supplied by the [[RPi Gertboard | Gertboard]]) is recommended which will help protect against damage. Alternatively, experiment with one of the [[RPi Tutorial Easy GPIO Hardware & Software#Alternative Test Platforms | Alternative Test Platforms]].

'''Extreme caution should be exercised when interfacing hardware at a low level, you may damage your RPi, your equipment and potentially yourself and others. Doing so is at your own risk!'''

==Aims==

Note:
The 12V relay driver circuit has been tested with real RPi device and was working properly.

==The Hardware==
The 12V relay driver circuit combines protection circuits described in [http://elinux.org/RPi_Tutorial_EGHS:GPIO_Protection_Circuits GPIO Protection Circuits].
Design was done with respect to maximize GPIO protection and minimize GPIO current withdraw.

[[File:Example.jpg]]

@@ Line 19: / Line 19: @@
 ==The Hardware==
 The 12V relay driver circuit combines protection circuits described in [http://elinux.org/RPi_Tutorial_EGHS:GPIO_Protection_Circuits GPIO Protection Circuits].
-Design was done with respect to maximize GPIO protection and minimize GPIO current withdraw.
+Design was done with respect to maximize GPIO protection and minimize GPIO current withdraw. The zener diode D1 protects the GPIO pins from over-voltage. R2 and LED D2 is used just to display port status, it may be removed. Transistor T1 is used to minimize current withdraw from GPIO 3.3V output pin. T1 drives the D2 as well as opto-coupler LTV 815. This opto-coupler is capable of driving load up to 80mA, so 12V relay is controlled directly if requires less than 80mA. D3 does relay high voltage protection.
-[[File:12v.relay.dtriver.png|400px|thumb|left]]
+[[File:12v.relay.dtriver.png|none|400px|thumb|left]]

← Older revision		Revision as of 21:46, 31 July 2012
Line 21:		Line 21:
	Design was done with respect to maximize GPIO protection and minimize GPIO current withdraw.		Design was done with respect to maximize GPIO protection and minimize GPIO current withdraw.

−	[[File:12v.relay.dtriver.png]]	+	[[File:12v.relay.dtriver.png\|400px\|thumb\|left]]

← Older revision		Revision as of 21:41, 31 July 2012
Line 21:		Line 21:
	Design was done with respect to maximize GPIO protection and minimize GPIO current withdraw.		Design was done with respect to maximize GPIO protection and minimize GPIO current withdraw.

−	[[File:~~3v3~~.relay.dtriver.png]]	+	[[File:12v.relay.dtriver.png]]

← Older revision		Revision as of 21:40, 31 July 2012
Line 21:		Line 21:
	Design was done with respect to maximize GPIO protection and minimize GPIO current withdraw.		Design was done with respect to maximize GPIO protection and minimize GPIO current withdraw.

−	[[File:~~Example~~.~~jpg~~]]	+	[[File:3v3.relay.dtriver.png]]