A Guide to Low-Voltage Output Plugs
Low-voltage DC power supplies use a wide variety of output plugs. Identifying the correct plug type, size, and polarity is essential for ensuring a safe and reliable connection. This guide provides a visual reference to the most common output plugs used in consumer and professional electronics.
Guide Index
- Concentric Barrel Plugs & EIAJ Plugs
- 3-Pin and 4-Pin Locking DC Plugs
- DIN and Mini-DIN Plugs
- Phono & RCA Plugs
- Modular & Mini IEC Plugs
Concentric Barrel Plugs & EIAJ Plugs
Concentric Barrel Plugs (Standard DC Plugs)
These are the most commonly used output plugs for low voltage power supplies. The dimension of the inside diameter (ID) is critical to ensure good electrical contact. A plug with an ID that is too small will not fit, whilst a plug with a larger ID than the jack will have an intermittent connection. The 2.1mm and 2.5mm ID versions are very easily confused.
| Outside Dia. (OD) | Inside Dia. (ID) | Length | Diagram |
|---|---|---|---|
| 5.5mm | 2.5mm | 8-14mm |  |
| 5.5mm | 2.1mm | 8-14mm | |
| 5.0mm | 2.1mm | 8-14mm | |
| 3.8mm | 1.35mm | 8-14mm | |
| 3.5mm | 1.35mm | 7-14mm |
EIAJ RC-5320A Plugs (Voltage-Coded)
Developed by the Electronics Industries Association of Japan (EIAJ), these plugs are similar to concentric barrel plugs but feature a yellow insulating ring and are coded by voltage classification. They are always wired with the centre pin as positive (+).
| Model | Voltage Class | OD | ID / Pin | Diagram |
|---|---|---|---|---|
| EIAJ-01 | 1 (3.15V) | 2.4mm | 0.7mm |  |
| EIAJ-02 | 2 (6.30V) | 4.0mm | 1.7mm | |
| EIAJ-03 | 3 (10.50V) | 4.8mm | 1.7mm | |
| EIAJ-04 | 4 (13.5V) | 5.5mm | 1.0mm Pin |  |
| EIAJ-05 | 5 (18.0V) | 6.5mm | 1.4mm Pin |
3-Pin and 4-Pin Locking DC Plugs
These DC plugs are commonly used for multi-output low voltage power supplies. They resemble Mini-DIN plugs but have larger diameter pins capable of carrying greater current. They often feature a locking mechanism for a secure connection.
| Model | OD | Length | Diagram |
|---|---|---|---|
| 3-Pin | 10mm | 6mm |  |
| 4-Pin | 10mm | 6mm |
DIN and Mini-DIN Plugs
DIN is an acronym for Deutsche Industry Norm which is the German standards organisation responsible for setting industrial standards for products made in Germany. Circular DIN plugs are available in 3 to 14 pins. The 5-pin version is available in either a 180° or a 240° pin-layout. Mini-DIN plugs are smaller, at 9.5mm in diameter.
| Type | OD | Pins | Diagram |
|---|---|---|---|
| DIN | 13.2mm | 3 to 8 Pins |  |
| Mini-DIN | 9.5mm | 3 to 8 Pins |  |
Phono & RCA Plugs
Phono Plugs (TRS/TS)
Phono plugs come in 3 diameters 6.3mm (1/4"), 3.5mm (1/8") and 2.5mm (1/16"). Each of the three diameters is available in mono (2-pole) and stereo (3-pole) versions. The mono version has one insulating ring (TIP & RING), while the stereo version has two insulating rings (TIP, RING & SLEEVE).
| Type | Sizes | Diagram |
|---|---|---|
| Mono (TS) | 2.5mm, 3.5mm, 6.3mm |  |
| Stereo (TRS) | 2.5mm, 3.5mm, 6.3mm |  |
RCA Plugs
A coaxial plug most commonly used for audio and video connections but occasionally used as a power supply output plug for devices like TV antenna power injectors. It is always wired with a positive centre pin and the shield as the negative or ground.
| Pin Diameter | Outer Diameter | Diagram |
|---|---|---|
| 3.70mm | 8.25mm |  |
Modular & Mini IEC Plugs
Modular Plugs (RJ Plugs)
Although these plugs were originally designed for telephony and data connections, they are now used for many other applications including output plugs for low voltage power supplies. Stock is available in 4, 6, 8, and 10 position configurations.
| Model | Availability | Diagram |
|---|---|---|
| 4, 6, 8, 10 Position | View Products |  |
Mini IEC Plugs
Three-pin miniature output plug used by electrical devices such as EFTPOS terminals which may require higher currents. Called a mini-IEC plug because its shape resembles the commonly seen larger IEC-C13 connector used for mains voltage appliances.
| Pins | Dimensions (A, B, C) | Diagram |
|---|---|---|
| 3 | 13.0mm, 9.0mm, 8.0mm |  |
Your Project, Perfected. That's The Access Advantage.
- Expert Local Support, Since 1973: Don't waste time with guesswork. Our experts have seen it all and are ready to provide the right solution, right now. Your success is our business.
- Uncompromising Aussie Quality: We live and breathe quality. From rigorous testing to official Australian certification, we guarantee every product we sell is built to perform and built to last.
- Your Specs, Your Brand, Our Build: Off-the-shelf not cutting it? We specialise in building custom cables and assemblies to your exact specifications, branded for your business. Let's create it together.
- Guaranteed for Life: Buy it once. Trust it forever. Our products are backed by a limited lifetime warranty, so you can invest in quality with zero risk. *Warranty excludes third-party brands such as HALO and UPS.
- Innovation That Keeps You Ahead: To ensure you always have access to the latest, most reliable solutions on the market, our catalogue is always changing with the tech landscape.
Let's get your project started.
Talk to an expert today for a custom quote or browse the solutions most relevant to your search.