9V

9V (later marketed as the Electric System or the 9V-powersystem, depending on country) was a voltage standard for electrical components (e.g. motors, lights) in many LEGO sets. It first appeared in 1985 in the Light & Sound series of Town and Space models that featured flashing lights and sirens, and was later expanded to the Monorail sets.

TECHNIC also moved over to the 9V system in 1990, with Trains making the change the following year.

The power came from a battery box with one 9V PP3 type battery (e.g. or later with 6x 1.5V batteries (TECHNIC, Basic). The 9V system sought to address the major weakness with the preceding 4.5V and 12V systems which was the pinned plug connectors that were prone to coming loose or the wires that would eventually fracture and fail after heavy use. The new system used special bricks that contained conductive elements built into the studs which were connected more positively and were more reliable over long periods of use. Wired connections were still used whenever power had to be transmitted through awkward routes, but the terminations used the conductive brick connectors in place of the pinned plugs.

The Trains theme was the only application of 9V that was powered by a mains DC Transformer and special metal conducting rails for 9V Trains (without any add-on center conductor rails that were used by the earlier 12V Trains system). Controversially however the 9V Trains system lost most of the accessories of the 12V system such as remote-controlled signals, points and lights.

Mindstorms used the 9V system until the release of Mindstorms NXT in 2006, which was backwards compatible with the 9V standard with use of 8528 Converter Cables for Mindstorms NXT.

The 9V standard was retired in 2009 and replaced with the Power Functions system, which used the same voltage and was backwards compatible with the 9V standard with use of 8871 Power Functions Extension Wire 20” and 8886 Power Functions Extension Wire.

9V Components[]

Wires & Adaptors[]

Image	#	Set	Number of pieces	Price	Release
	5120	Polarity Reversal Switch for 8082 (9V)	2	$5.50	1993
	5041	Space Track Connector Lead 9V	1		1988
	970041	128 MM Connecting Leads	3	$9.70	2002
No image	9897	9 V Connecting Leads	3		1998
No image	9898	9 V Long Connecting Leads	2		1996
	5111	9V Motor Wire, 128cm	1	$3.99	1990
	10078	Train Connection Wire	1		2003
	8528	Converter Cables for Mindstorms NXT	3		2006
	8871	Power Functions Extension Wire 20”	1	$3.99 / €4.69	2009
	8886	Power Functions Extension Wire	1	$2.99	2008

Power Sources[]

Image	#	Set	Number of pieces	Price	Release
No image	9753	TECHNIC Control Center	15		1993
	4548	Transformer and Speed Regulator	3	$42.00	1992
	5115	Technic Battery Box 9V	1	$11.00	1991
No image	9831	9 V Battery Box with Switch	1		1994
	5293	Battery Box - Basic and TECHNIC	1	$12.25	1996
	5038	Battery Box 9V Electric System	1		1988
	5391	9V Battery Box	1	$5.00	1997
	9912	LEGO Solar Cell	1	$44.95	1999
	9916	Capacitor	1	$15.00	1999
	9709	RCX Programmable LEGO Brick	1	$109.99	1998

Motors[]

#	Set	Number of pieces	Price	Release
5011	9V Basic Motor	1	$27.00	1993
5040	Monorail 9V Motor for Space Track	1		1988
5114	Technic Motor 9V	1	$16.00	1991
5300	Train Motor 9V	3		1991
10153	9V Train Motor	3	$25.00	2002
8866	Train Motor	7	$10.99 / €12.99	2009
5225	TECHNIC Geared Motor	1	$15.75	1998

Lights & Sounds[]

#	Set	Number of pieces	Price	Release
5307	Head Light Brick	3		1992
970005	9-Volt 1 x 2 Lamp Brick	2		2002
0005	1x2 Lamp Brick, 9V	2	$10.00	2008
846	Lighting Set, 9V	39	$17.99	1992
3748	Light Unit for Train	4	$9.99	2001
5033	Light and Sound 1 x 4 Lighting Brick and 4 Colour Globes	5	$5.50	1987
5034	Light and Sound 1 x 2 Lighting Brick and 4 Colour Globes	5		1987
5308	Headlight Bricks	3		1994
5310	Light Brick Conductor (9 V)	4		1996
1172	Replacement Light & Sound 1x2 Lighting Brick with Coloured Globes	5		1986
5034	Replacement Light & Sound 1x2 Lighting Brick with Coloured Globes	5		1987

Sensors[]

#	Set	Number of pieces	Price	Release
9911	Touch Sensor and Leads	3	$12.00	2004
9756	Rotation Sensor	1
9755	Temperature Sensor	1		1999
9757	Touch Sensor	2		1999
9758	Light Sensor	1		1999
9888	Touch Sensor	1		2002
9889	Temperature Sensor	1	$25.00	2004

Train Tracks[]

#	Set	Number of pieces	Price	Release
4515	Straight Rails	8	$13.25	1991
4520	Curved Rails	8	$13.25	1991
4531	Manual Points with Track	6	$28.00	1991
4519	Rail Crossing	1	$10.00	1999
2159	9V Train Track Starter Collection	24	$29.99	2006
4206	9V Train Switching Track Collection	27	$44.99	2006

Combination Sets[]

#	Set	Number of pieces	Price	Release
9203	Deluxe Lighting Kit			1993
624	Basic Motor, 9V	27	$26.00	1996
8720	9V Motor Set	57	$35.99	1990
845	Battery Motor, 9V	27		1992
9615	Motor Add-On for Simple Mechanisms	3	$31.99	1997
8287	Motor Box	93	$29.99	2006
8735	Motor Set, 9 volt	60	$39.99	1997
K4548	9-V Train Accessory Collection	22	$96.97	2007

9V Powered Sets[]

Basic[]

Image	#	Set	Number of pieces	Minifigures	Price	Release
	735	Basic Building Set	537			1990
	4223	Basic Building Set	546			1998

Town[]

#	Set	Number of pieces	Minifigures	Price	Release
6399	Airport Shuttle	743	9		1990
6430	Night Patroller	140	Police Officer		1991
6440	Jetport Fire Squad	159	Firefighter (x2)		1991
6450	Mobile Police Truck	77	1 Police Officer	$18.75	1985
6480	Hook and Ladder Truck	118	1 Fireman	$23.00	1985
6481	Construction Crew	168	2		1989
6482	Rescue Helicopter	198	3		1989
6483	Coastal Patrol	243	Police Officers (x3)	$47.99	1994
6484	F1 Hauler	269	Mechanic (x2), Ben Steer		1995

Space[]

#	Set	Number of pieces	Minifigures	Price	Release
6750	Sonic Robot	103	Blue Classic Spaceman, Spaceman Reed		1986
6770	Lunar Transporter Patroller	118	Yellow Futuron Astronaut	$26.75	1988
6780	XT Starship	201	Yellow Classic Spaceman		1986
6781	SP-Striker	230	Blacktron Astronaut, Space Police I Officer	$28.00	1989
6783	Sonar Transmitting Cruiser	345	Red Classic Spaceman, Yellow Classic Spaceman, Robot OK	$55.00	1986
6990	Monorail Transport System	715	Blue Futuron Astronaut (2), Yellow Futuron Astronaut (3)	$155.00	1987
6991	Monorail Transport Base	573	Unitron Chief, Unitron Astronaut (x2), Major Kartofski	$178.00	1994
6979	Interstellar Starfighter	292	Alpha Draconis, Chamon, Andy Droid	$80.00	1997
6988	Alpha Centauri Outpost	406	Blacktron Future Generation Astronaut (x5)	$80.00	1991

Trains[]

#	Set	Number of pieces	Minifigures	Price	Release
4559	Cargo Railway	842	7	$139.00	1996
4512	Cargo Train	544	3	$140.00	2003
3225	Classic Train	281	3		1998
4551	Crocodile Locomotive	314	1		1991
4534	LEGO Express	34	5	$159.99	2002
4535	LEGO Express Deluxe	762			2002
4565	Freight and Crane Railway	914	3		1996
4564	Freight Rail Runner	587	3	$134.00	1994
4511	High Speed Train	336	3		2003
K2159	Holiday Train Starter Collection	991	7	$165.99	2006
4563	Load and Haul Railroad	476	3		1991
10001	Metroliner	772	Passenger (x7), Mayor Brickman, Train Driver, Railway Employee (x2)	$149.00	2001
4558	Metroliner	768	Passenger (x7), Mayor Brickman, Train Driver, Railway Employee (x2)	$149.00	1991
10132	Motorized Hogwarts Express	708	Harry Potter, Ron Weasley, Professor Lupin, Dementor		2004
4560	Railway Express	658	9		1999
4561	Railway Express	665	9	$139.00	1999
65537	Classic Freight Train	613		$80.00	2004
65801	Trains Value Pack	735	5		2005
K10173	Complete Holiday Train Collection	997	7		2006
7898	Cargo Train Deluxe	856	5	$102.75 / €169.99	2006
7897	Passenger Train	501	Train Conductor, Passenger (2)	$89.99 / €89.99	2006

TECHNIC[]

#	Set	Number of pieces	Minifigures	Price	Release
8094	TECHNIC Control Center	554			1990
8082	Multi Model Control Set	459		€69.99	1993
8868	Air Tech Claw Rig	954		$139.99	1992
8457	Power Puller	960	1	$99.99	2000
8480	Space Shuttle	1366		$157.99	1996
8064	Universal Motor Set	219		$54.99	1990
8421	Mobile Crane	1884		$149.99	2005
8266	Spyder Slayer	363	2	$69.99	1998
3038	Super Challenge	366	2 TECHNIC Figures	$69.99	1998
8456	Fiber Optic Multi Set	404		$74	1996
8479	Barcode Multi-Set	1280		$163.99	1997
8483	CyberMaster	900	1 TECHNIC Figure		1998

Mindstorms, Educational, and Dacta[]

#	Set	Number of pieces	Minifigures	Price	Release
9633	Advanced Air Power Set	238			2002
9665	Mechanical Engineering	318		$149.99	1985
9609	Technology Resource Set	1733			1995
9702	Control System Building Set	220	2		1993
9725	ROBOLAB Amusement Park Set	301	5	$99.99	1998
9680	Energy Work, Power Starter Set	804		$250.00	1999
9681	Renewable Energy Set	710			1999
9684	Renewable Energy Set	729	4	$169.99	2003
9685	Green Car Set	47			2003
9665	Mechanical Engineering	318		$149.99	1985
9609	Technology Resource Set	1733			1995
9702	Control System Building Set	220	2		1993
9725	ROBOLAB Amusement Park Set	301	5	$99.99	1998
9719	Robotics Invention System	727		$200.00	1998
9747	Robotics Invention System	727		$200.00	1999
3804	Robotics Invention System 2.0	717		$189.99	2001
9730	Robo Sports	91		$50.00	1998
9732	Extreme Creatures	149		$50.00	1998
9780	ROBOLAB Starter Set	1702	4		1998
9735	Robotics Discovery Set	387		$150.00	1999
3801	Ultimate Accessory Set	45			2000
9736	Exploration Mars	156		$49.99	2000
3800	Ultimate Builders Set	321		$60.00	2001