![]() In other words, as a voltage source, these batteries were much stiffer and had a better transient response with respect load regulation, droop, and recovery.įor many designers, it’s not so much about pulse power in the classic sense as it is about the dynamics of load regulation. In contrast, the voltage output of the no-name alkaline AA batteries only dropped to 11.5 V-close to open-circuit nominal of 12.8 V (8 × 1.6 V)-and popped back to 12 V in about 10 msec. Unfortunately, that 50-ms window is when the printhead is expecting to receive full current for heating. Its transient response was revealing: when called upon to deliver full current to drive the label-maker’s thermal printhead, the voltage dropped down to a few volts for about 50 milliseconds, then rose to nominal voltage and delivered the needed current. (It’s all low voltage, so there was no danger the only risk was shorting something out and ruining the unit.)įigure 4 Accessing the power section of the label maker was fairly easy remove a few screws and separate the unit’s top and bottom halves. I opened up the label maker so I could access and monitor the delivered supply voltage, Figure 4. Perhaps I shouldn’t have been surprised, but the label-maker did not work with the adapter. I went online and bought one rated for 9.5V/1.6A, which claimed to be a fit for this specific unit’s requirements it had the right voltage, current, and barrel-connector size. No problem, I figured: the unit has a barrel connector for an external AC/DC adapter. Since I only use it every few months, it seemed prudent to not leave the batteries in, yet putting them in and removing them each time was a nuisance (plus, I had to find the eight batteries!). I have a small, basic Brother laminated-label maker which uses 8 AA batteries, Figure 3.įigure 3 This Brother label maker takes 8 AA cells and has a barrel-connector port for an external AC/DC supply. Note that not all pulse-power applications involve sophisticated designs or scientific experiments some are pulse-like but on a much smaller scale. At the same time, the power source here is not a pulse-supply, but a “stiff” conventional power supply with good superior dynamics on its load-side regulation. The current on the low-voltage core’s supply may ramp from tens of milliamps to tens of amps in microseconds and do so without overshoot or ringing. Consider a high-end processor (video, data, AI, or FPGA) which is in low-power states, then must quicky ramp up to handle a specific task. There are also many smaller-scale applications which are not formally considered pulse-power situations but have some of their attributes. In most cases, the pulse rise time must be fast (microseconds or faster), so every subtle impediment to slewing, such as parasitic inductance or capacitance, must be identified and minimized. The challenge of pulse power is not just achieving the balance between accumulating energy and then expending it as power in a brief burst. Source: SLAC National Accelerator Laboratory This pulsed power is usually produced by transferring energy stored in capacitors and inductors to a load very quickly via switching devices, Figure 2, or topologies such as Marx generators.įigure 2 Pulse power usually starts with energy stored as a voltage in a capacitor (top) or current in an inductor (bottom) and a fast-acting switch to release that energy, but there is obviously much more than that to a viable source. For example, repetitively pulsed lasers used for welding typically need power on the order of one kilowatt with a pulse repetition rate of about 1000 pulses per second.ĭesigning a supply which can deliver pulsed power, where the output voltage and/or current must ramp from idle to full in a few milliseconds or even microseconds, is a challenge. ![]() Applications of pulsed power include recycling, energy research, laser-based weapons, electromagnetic launchers for aircraft, material processing, medical treatments and systems, and food and agriculture.Īlthough we tend to associate conventional power sources and supplies with a somewhat more “steady-state” power delivery, there are many applications and situations which call for pulse-like performance. It often has extremely high power but moderately low energy. That phrase usually refers to the science and technology of accumulating energy over a relatively long period of time and releasing it as a high-power pulse composed of high voltage and current but over a short period of time. The NIF project is an extreme example of pulsed power.
0 Comments
Leave a Reply. |