Appropedia is looking for service learning partners. Instructors, supervisors, and students interested in internships, please contact us.

Low voltage connection basics

From Appropedia

Jump to: navigation, search
This page is in Appropedia's offline content bundle.
This page needs review for grammar, spelling, clarity and/or layout.
You can help by editing this page.

Comment:{{{1}}}



Contents

[edit] What is AC voltage?

AC voltage is voltage that does not have a Plus and Minus terminal on the supply.

AC voltage symbol:

Other names for AC voltage:

  • Directed power or voltage
  • Sine wave power or voltage
  • Inverter type of power or voltage

[edit] AC voltage safety

AC electricity with a voltage less than 50 V (RMS) is called Extra Low Voltage. This voltage is unlikely to give a human being a dangerous electric shock.

[edit] What is low voltage?

Other names for low voltage:

  • Shock free power or voltage

[edit] What is DC voltage?

DC voltage is voltage that has a Plus and Minus terminal.

DC voltage symbol:

Other names for DC voltage:

  • DC power or voltage
  • Battery type of power or voltage
  • Plus-minus power or voltage


[edit] Electric DC polarity: plus and minus

Electricity basics: Marked plus wire

For most kinds of devices it is important to have the right voltage and polarity. Wrong voltage or polarity can destroy a device

How to mark the plus or to find the plus pole:

  • Red is always plus.
  • Painted line on the plus wire, no painted line on the min.
  • Square wire is plus, round wire is minus.
  • Sharp edge is plus, round wire is minus.
  • Knot is plus, no knot is minus.
  • Mark on the plus wire, the plus wire is special.
  • and so on, the plus wire is special or not normal than a normal wire.



These must be in good working order to save your electric material:

  • The voltage.
  • The amperage.
  • The plus and minus position.
  • The type of power, AC or DC.
  • The type of low voltage coax connector.
  • Protect your plug and connector against mechanical pulling force.
  • Take your time to check these 6 items.



Side and middle electric connection


sign on power output or this sign sign on power consumption or this sign harmful for output ? harmful for power consumer ?
no no
no no
no YES !
no YES !
DC AC no YES !
AC DC no YES !

[edit] Electric current ampere

amp. on

power output

or this amp. amp. on

power consumer

or this amp. harmful

for output ?

harmful for

power consumer ?

500 mA =0.5 A 500 mA =0.5 A no no
400 mA =0.4 A 500 mA =0.5 A YES ! no
500 mA =0.5 A 400 mA =0.4 A no no

[edit] Electric voltage

volt output volt consumer harmful for

output ?

harmful for

power consumer ?

12 V 12 V no no
9 V 12 V no does not work well
3 V 12 V no does not work
12 V 9 V no YES !

[edit] Adapter with different connectors

Protect your power supply.

On the left is the power supply output and on the right power receiving device.


.

Plus and minus

Adapter connectors

OUTSIDE

(mm)

INSIDE

(mm)

Shortcut Plug Type

(code)

mark
6.5 1.0 no AA =
6.5 1.75 no AB =
2.5 2.5 YES! A (*) =
3.5 3.5 YES! B (*) =
3.0 1.0 no C =
5.0 2.1 no D =
5.5 2.1 no E =
5.0 2.5 no F =
5.5 2.5 no G =
3.5 1.35 no H =
4.0 1.7 no I =
4.75 1.75 no J =
5.0 1.5 no M =
5.5 1.5 no N =
5.5 5.8 no P =
6.3 3.0 no Q =
7.0 1.0 no R =
2.35 0.75 no S =

(*) Mono jack

[edit] What is an electrical short?

An electrical short is when the plus and minus are in contact with each other.

This is harmful for the adapter or battery.

[edit] Electrical short with (dis)connecting device

Some smaller connectors shortcut the power supply if you (dis)connect .

(dis)Connect the connector to the device if there is NO power on the plug.


Right


[edit] Car cigarette lighter plug

A car cigarette lighter plug must have the plus in the middle and the minus on the outside.

Some female car sockets have 24 volts.


[edit] See also

[edit] Interwiki links

external links

Retrieved from "http://www.appropedia.org/Low_voltage_connection_basics"
Personal tools