ZM500-RS Resonant Switching 500W PSU Discontinued
More variations available Show

Zalman ZM500-RS Resonant Switching 500W PSU

The first of its kind in the PC market, Zalman’s new Resonant Switching power supply offers the size, cost and efficiency characteristics of a standard switch-mode power supply, but with drastically reduced EMI (electromagnetic interference).

Zalman ZM500-RS Resonant Switching Power Supply

Brand new: Resonant Switching Circuit

We are pleased to present Zalman’s new mid-range power supply which pioneers a complete circuit redesign, utilising a new “resonant switching” system which compares very favourably with standard switch-mode power supplies in several areas. Firstly, EMI (electromagnetic interference) is drastically reduced, meaning that the unit operates much more “cleanly” from an electromagnetic point of view.

In addition, unwanted heat generation is reduced by minimising “switching loss” through a technique called Zero Voltage Switching (ZVS). Furthermore, the need for an output inductor is eliminated, leading to outstanding stability and reliability and reduced electromagnetic and acoustic noise. Because less heat is produced as an effect of improved efficiency, the unit’s (already very quiet) fan can run more slowly which in turn means even quieter operation.

Dual independent 12V rails and Resonant Switching circuitry
6+2-pin and 6-pin PCI-E video card power connectors
ATX12V (4-pin) and EPS12V (8-pin) CPU power connectors
ATX20+4-pin mainboard power connector
Twin SATA power connectors

Safety, reliability and quietness

The ZM500-RS offers multiple safety features including over-voltage protection, over-current protection, short-circuit protection, under-voltage protection and over-temperature protection. As you would expect, it passes all internationally recognised safety approvals and electromagnetic compatibility (EMC) certifications, including UL, FCC, CE, CB and KCC.

It comes with mounting screws, cable ties and a user manual and unlike modular power supplies, all cables are permanently attached to the unit meaning you won’t need to go looking for them when the time comes to upgrade and add another drive or card to your PC! It has two independent +12VDC rails, so you can be sure that any voltage ripples or current spikes caused by your graphics cards or peripherals will not appear on the supply feeding your processor and motherboard, translating into extra stability and reliability.

Unsurprisingly, the fan is a top-quality unit with hydro bearing for low noise and long life (150,000 hours expected lifespan, or if you prefer, over 17 years!). Its control circuit is linked to an internal temperature sensor, so the fan will only ever increase in speed if the unit detects that it is working hard and needs a little extra cooling. At all other times, the fan will run at a minimum nominal speed, providing you with a quiet and comfortable computing environment.

ZM500-RS Cable Loom

Features

Brand new Resonant Switching circuit design for high efficiency and low EMI
ATX12V v2.3 compliant
87% maximum efficiency – 80 PLUS Certified
Two independent +12VDC power rails
Ultra-quiet 120mm fan with hydro bearings
NVIDIA SLI and ATI CrossFire Ready
3 year warranty

Specifications	ZM500-RS
Form factor	ATX12V v2.3 / EPS 12V
+3.3V max load	24 A
+5V max load	24 A
+12V1 max load	18 A
+12V2 max load	18 A
Combined maximum output +3.3V / +5V	130 W
-12V max load	0.5A
+5VSB maximum standby current	3.0 A
PFC Type	Active PFC
Power Factor	99% max
Power conversion efficiency	87% max @ 230 VAC
Number of hard drive connectors	4
SATA connectors	2
Number of floppy drive connectors	1
Dimensions, mm	140(L) x 150(W) x 86(H)
ATX12V (4-pin)/EPS12V (8-pin) support	Yes, splitter
20/24-pin ATX connector	Yes
PCI-E support	One 6-pin and one 8/6-pin
Mains input voltage	100-240 VAC, 50-60 Hz
Fan speed control	Thermal
Over voltage protection	Yes
Over current protection	Yes
Short circuit protection	Yes
Over temperature protection	Yes
Under voltage protection	Yes
EMC, safety approvals	CE, CB, UL, KCC, FCC
Mains input voltage selection	Auto-range
Length of motherboard power cable	45 cm (approx)
Fan speed	800 RPM - 1250 RPM depending on load
Acoustic noise level	18-25 dB depending on fan speed
Warranty	36 months

Specifications	ZM500-RS
Form factor	ATX12V v2.3 / EPS 12V
+3.3V max load	24 A
+5V max load	24 A
+12V1 max load	18 A
+12V2 max load	18 A
Combined maximum output +3.3V / +5V	130 W
-12V max load	0.5A
+5VSB maximum standby current	3.0 A
PFC Type	Active PFC
Power Factor	99% max
Power conversion efficiency	87% max @ 230 VAC
Number of hard drive connectors	4
SATA connectors	2
Number of floppy drive connectors	1
Dimensions, mm	140(L) x 150(W) x 86(H)
ATX12V (4-pin)/EPS12V (8-pin) support	Yes, splitter
20/24-pin ATX connector	Yes
PCI-E support	One 6-pin and one 8/6-pin
Mains input voltage	100-240 VAC, 50-60 Hz
Fan speed control	Thermal
Over voltage protection	Yes
Over current protection	Yes
Short circuit protection	Yes
Over temperature protection	Yes
Under voltage protection	Yes
EMC, safety approvals	CE, CB, UL, KCC, FCC
Mains input voltage selection	Auto-range
Length of motherboard power cable	45 cm (approx)
Fan speed	800 RPM - 1250 RPM depending on load
Acoustic noise level	18-25 dB depending on fan speed
Warranty	36 months

Customer Reviews

Really fine PSU

Anonymous, 9th February 2010

I’m very happy with this PSU. All the cables have been put into sheaths and tie-wrapped, making them ultra neat and less likely to be a problem within your case. The build quality is very high and the unit is super-quiet. I also thought it was a nice touch to supply this with a mains cable and extra tie-wraps and mounting screws.

Product Resources

FAQ

Do high wattage power supplies cost more to run?
No - the rated wattage of a power supply refers to the maximum amount of power it can deliver at full load, not how much power it uses. More powerful PSUs will consume around the same amount of power as lower powered power supplies in any given PC system, so your electricity bill will not be higher when using a more powerful power supply!

The best way to reduce your electricity bill when using your PC is to use a more efficient power supply or make your PC consume less power by removing components which are not needed, such as extra drives and expansion cards, or by choosing a cooler-running processor or graphics card.
My brand new power supply doesn’t work! Am I doing something wrong?
It’s possible that the power supply may be faulty, but here are some simple things to check. Firstly, a power supply will not work if you simply plug it in and flick the switch. The power supply will only turn on if you connect it to a working motherboard and associated items (processor, memory, video card, etc). It is actually the motherboard which tells the power supply when to switch on.

Secondly (if applicable), check the voltage is set correctly to 115/230 volts depending on what country you are in. Thirdly, if possible it would be good to try the power supply in another PC to see if it works, or try another power supply in your PC to see if that works. You can then tell whether it is the power supply which is faulty or the actual PC itself. If all else fails, please contact us for further support, and/or return details.
Why should I buy a whole new PSU when I could just replace the noisy fan in my existing one?
Virtually all the noise generated by a PC power supply originates from the cooling fan inside it, so simply replacing the fan with a quiet fan may seem an obvious way to go. However, if you are thinking about attempting this operation, please bear the following points in mind:
1. Your existing power supply will be designed to run with a specific amount of airflow in order to adequately cool the components inside and reducing the airflow may lead to overheating and damage to the power supply and/or PC.
2. All PC power supplies contain very high voltages and even with the power disconnected, the voltages stored in the capacitors can be easily enough to kill. It is not recommended to take the cover off any PC power supply for this reason unless you are absolutely confident of your own ability. Because of the grave dangers involved, all PC power supplies by law carry a warning label forbidding removal of the power supply case.
3. There will be no standard PC fan connector inside the power supply to use to connect a replacement fan, and it would probably have to be soldered directly into the PCB inside the power supply, or have a specialist power connector attached. This can be a tricky operation to say the least.
Please consider the above points very carefully before proceeding with an operation to replace the fan in your existing power supply!
What is PFC (Power Factor Correction)?
If you are interested in being “green” and saving the planet, you might like to read a short explanation of how our power supplies can save energy using Active PFC (Power Factor Correction), not to be confused with Power Conversion Efficiency which is also very good in most of our PSUs. “Power Factor” is a measure of how efficiently electrical power is consumed. Ideally, Power Factor would be 1 (or 100%) and known as unity.

Unfortunately in the real world, Power Factor is reduced by highly inductive loads down to values of 0.7 (70%) or less. This induction is caused by equipment such as small electric motors, fans, fluorescent lighting ballasts and transformers such as those in PSUs. This is bad news for the electricity generating companies who can impose a surcharge on heavy users if they have a consistently low Power Factor, as more electricity has to be produced to make up the shortfall.

Power Factor Correction (PFC) is used in some equipment to minimise the inductive component of the electrical current. This helps to reduce the losses in the electrical supply to that equipment. Power Factor Correction capacitors are normally used to reduce induction in an electrical load, which minimises wasted energy and hence improves the efficiency of a company and reduces electricity costs.

It is not usually practical to reach unity, i.e. Power Factor 1, and it seems that most electricity supply companies accept consumers having a Power Factor as low as 0.94 (94%) without imposing a surcharge. Unfortunately most of the cheap (and not so cheerful) PSUs tend to have a Passive PF as low as 0.75 or 75% which in a large office can lead to a PF surcharge.

However, the good news is that most of Quiet PC’s PSUs implement a system known as Active PFC which involves some clever electronics. This means that their power factor (PF) can be as high as 0.94 or 94% (at full load), while harmful harmonic frequencies are reduced to well below legal requirements. So by using our products, you can be happy in the knowledge that you are doing your bit to save the planet!
How do I know what size of wattage power supply I need?
The best answer we can give to this question is to go ahead and take an intelligent “guesstimate"! There are no hard and fast rules about what size of power supply any given PC needs as a minimum. Our advice would be that if you are replacing an existing power supply, then consider a new one at least of the same wattage as the old one. In addition, if you wish to build in a “safety margin” to allow for reliable running and possible future upgrades, consider adding 100-200 watts to the rating of your existing unit.

If you are building a new PC, most customers now buy a power supply rated in the region of 500-800 watts depending primarily on the performance level of their graphics card(s) and number of drives to be installed. But in any event if you are unsure about which power supply would be best for your PC then please do contact us by phone or email and we will be happy to give you a specific recommendation based on your budget.
My new PSU came with a 24-pin connector but my motherboard needs 20 pins! Do I need an adaptor cable?
We receive many customer enquiries about this. In fact, most of the 24-pin compatible power supplies we sell come with special motherboard connectors which can be converted to 20-pins with no additional conversion cables. All you need to do is look carefully at the connector and you will see that the end four pins can be slid off, turning the connector into a 20-pin compatible one (see below) - easy when you know how!

Image showing how to change a power supply’s 24-pin motherboard connector into a 20-pin connector by unclipping the end four-pin block
What do the PSU safety protection abbreviations mean?
There are many possible safety protections a PSU can have. Below is a list of what each abbreviation means. Please note, not all PSUs have all safety protections.

OCP - Over-Current Protection

OVP - Over Voltage Protection

UVP - Under Voltage Protection

SCP - Short Circuit Protection

OPP - Over Power Protection

OTP - Over Temperature Protection

UL - Underwriters Laboratories, more information.

TÜV - Technical Inspection Association, more information.

CE - European Conformity, more information.

FCC - Federal Communications Commission, more information.

RoHS - Restriction of Hazardous Substances Directive, more information.

WEE - Electronic waste, more information.

80 PLUS - Promotes energy efficiency for PC power supplies, more information.

ErP - Energy Related Products, more information.

More information on certification marks can be found here.