Manufacturer of Programmable AC Power Sources - Associated Power Technologies, Inc.

FAQs

Our FAQ section is designed to answer questions regarding terminology, and instrument features. It allows you to have your questions answered while providing a comprehensive overview of our industry, and our products and services.

What are some advantages of a switching power supply?
What are some advantages of a linear power supply?
What is VA?
What is True Power (WATTS)?
What is Power Factor?
What is Crest Factor?
Can APT´s power sources connect to a computer?
What is the difference between RS-232 and GPIB?
What is the difference between an AC Power source and an AC Power supply?
What type of power source does APT manufacturer?
Does APT offer stock delivery?
Does APT offer extended warranties?
If I modify my instrument will that void my warranty?
What type of protection circuits do APT products incorporate?
How do I return an instrument for service or calibration
What is your turnaround time for service work?
What is the difference between AC current and DC current?
What is frequency?
What is inrush current?
What is OC Foldback?
What is steady state current?
What is THD?
What do you mean by response time?
What is PWM (Pulse Width Modulation)?

Q.	1. What are some advantages of a switching power supply?
A.	The Switching supply achieves its output regulation by means of one or more active power handling devices which are alternately placed in the on and off state. Many switching supplies use pulse width modulation to control the output. The switching power supplies typically are smaller and lighter than linear supplies, and are more efficient. TOP ^
Q.	2. What are some advantages of a linear power supply?
A.	The linear supply offers low noise, low distortion and fast transient response but it is less efficient due to its larger size as well as being much heavier. TOP ^
Q.	3. What is VA?
A.	The VA rating of the power supply pertains to the sizing of the power supply. The VA rating of the power source is the true RMS current multiplied by the true RMS voltage. It is also considered Apparent Power. TOP ^
Q.	4. What is True Power (WATTS)?
A.	True Power is the amount of work performed by an energy source over time. In AC circuits it takes into account non-sinusoidal wave shapes and leading and lagging current which are caused by reactive loads. TOP ^
Q.	5. What is Power Factor?
A.	Power Factor is the ratio of the actual power of the alternating current as measured by a wattmeter to the apparent power as indicated by an ammeter and voltmeter. It can also be defined as the cosine of the phase angle between the voltage applied to the load and the current passing through it. Inductive and Capacitive loads will cause a phase shift in the current. A perfect power factor is 1:1. TOP ^
Q.	6. What is Crest Factor?
A.	Crest Factor is the ratio of the Peak to RMS of a waveform. The Crest Factor of a true sinusoid waveform is 1.414. Non-sinusoidal waveforms can have crest factors that are above or below 1.414. TOP ^
Q.	7. Can APT´s power sources connect to a computer?
A.	Yes, our 6000 series of AC power sources come standard with RS-232 serial interfaces. We also have available optional GPIB or Ethernet interfaces. TOP ^
Q.	8. What is the difference between RS-232 and GPIB?
A.	The RS-232 interface is a serial interface that allows customers to directly connect a tester to a PC. This is primarily used to connect a computer to a single test instrument. The GPIB Interface, sometimes called the General Purpose Interface Bus, is a digital interface system that can be used to transfer data between two or more devices. The GPIB interface gives the operator the ability to control up to 15 instruments on a single bus. TOP ^
Q.	9. What is the difference between an AC Power source and an AC Power supply?
A.	These terms, along with Frequency Converter are commonly used interchangeably. Technically, speaking an AC power source is an instrument that takes one AC voltage and frequency level and converts it into another AC voltage and frequency level. An AC power supply is an instrument that simply generates AC voltage, current, frequency and power to operate a device. TOP ^
Q.	10. What type of power source does APT manufacturer?
A.	All of our power sources are switching power sources. TOP ^
Q.	11. Does APT offer stock delivery?
A.	Yes, all of our standard items are available for stock delivery. In fact we guarantee that any new order will ship within 24 hours of the Purchase Order being received or we will pay the freight. TOP ^
Q.	12. Does APT offer extended warranties?
A.	Yes, we offer a 3 year extended warranty and a 5 year extended warranty. Our 3 year warranty is available for purchase along with our power source. It includes all the benefits of our standard one year warranty, plus annual calibration for two years. The opportunity to extend our warranty for up to five years is also available to our customers. All that is required is that you return your power source to our factory for annual calibration and inspection. We will extend its warranty then for each year up-to 5 years. You can learn more about our warranties right at our warranty page (hyperlink to warranty page). TOP ^
Q.	13. If I modify my instrument will that void my warranty?
A.	Yes. Any non-factory modification will void your warranty. In addition, it is our policy that should we find any unauthorized modifications during service work that could compromise operator safety we will return the instrument to its original specifications and safety level and charge you accordingly. TOP ^
Q.	14. What type of protection circuits do APT products incorporate?
A.	We offer several enhanced protection circuits: Over Current Protection (OCP), Over Temperature Protection (OTP), and Over Voltage Protection (OVP). OCP is a protection circuit used to protect the power source from an over current condition that may occur from the load. OTP is a protection circuit used to protect the power source from an over temperature condition that may occur from the load. OVP is a protection circuit used to protect the power source from an over voltage condition that may occur from the load. TOP ^
Q.	15. How do I return an instrument for service or calibration?
A.	Please call our Customer Support Center at 1-877-322-7693 (USA and Canada only), or 1-909-860-1646, and request a return material authorization number (RMA). Please return the instrument in its original packing materials with the freight prepaid. Enclose any special instructions and a brief explanation of what is wrong with the instrument or what services you would like performed. TOP ^
Q.	16. What is your turnaround time for service work?
A.	Our turnaround time for both calibration and service repair work leads the industry. We guarantee 24 hour turnaround time for calibration service or we pay the return shipping. Likewise, we guarantee a 48 hour turnaround time on all repair service work or we pay the return shipping. TOP ^
Q.	17. What is the difference between AC current and DC current?
A.	The term AC current, alternating, is used to describe the flow of current. A graphical representation would be a sine wave in which the current moves from a positive to a negative cycle from 0º to 360º. DC current, direct, describes the flow of current. A graphical representation would be a straight continuous line in which current moves in one direction in either a positive or negative output. TOP ^
Q.	18. What is frequency?
A.	Frequency is the number of times a waveform completes a cycle in a period of time. TOP ^
Q.	19. What is inrush current?
A.	Inrush current is the amount of current that a load needs to power up. Some loads require a large inrush starting current in order to operate. TOP ^
Q.	20. What is OC Foldback?
A.	OC Foldback is a feature / technology used in power sources. This technology reduces the output current linearly to the voltage in order to power loads that may have a high inrush current. TOP ^
Q.	21. What is steady state current?
A.	Steady state current is the term used to describe the current when the load is running nominally after the inrush current. TOP ^
Q.	22. What is THD?
A.	THD stands for Total Harmonic Distortion. This is a percentage that is used to identify a level of noise/unclean incorporated into the output waveform is that is generated by the power source. TOP ^
Q.	23. What do you mean by response time?
A.	Response time is the time that is needed to regulate the voltage, current, frequency, and power output when a load is added to the power source. TOP ^
Q.	24. What is PWM (Pulse Width Modulation)?
A.	Pulse Width Modulation is a type of modulation that compares a high frequency carrier waveform to an input signal, creating a square wave output whose pulse width is determined by where the current value is along the sine wave. TOP ^