SLAP (Sealed Lead-Acid battery power supply unit)
Design consideration of KingRex SLAP
The slightest demand, the greatest satisfaction!
After T20 series audio amplifier appear to the public, KingRex keep thinking how could we match user’s demand and how could we increase the value for T20. KingRex provides two power solution for the users- power adaptor (switching type) & power supply unit-PSU(linear power type). KingRex believes these two power source could match almost all the users demand not only by its reasonable price and excellent quality but also the soundstage which could provide. Nevertheless, there is still very few group has further demand for the pure power source. So KingRex design and create the new updated power unit –SLAP (sealed lead-acid battery power supply unit) to pleased the music connoisseur by the clarified power source with sterling sonic performance.
How is the difference between switching power, linear power, and battery power?
All of the amplifiers need current while them working, or there won’t be any good sonic performance as many detail will lost. So the power source is very important for the amplifiers. There will be three power sources most in common: switching power adaptor, linear power supply unit, and battery power supply unit. he switching power adaptor should be most convenience and common power source the users could chose however it is not a good selection for music connoisseur who cares the sonic performance much more than the obtain convenience as it has the most noise and distortion by the high-frequency switching and harmonics in its design.
The linear power supply should be better choice for audiophiles. It has less noise and distortion than the switching power adaptor, however, during the AC to DC conversion and rectification process, there is still unavoidable following the unexpected noise and distortion. That’s because the AC power should pass lots of electronic parts as transformer, diodes, voltage regulators, and components to be the lower current and neat DC.
As some connoisseur might need purer power source to extend the sonic performance, we create the SLAP
Why SLAP(battery power) is better than PSU(linear power supply)?
Pure DC power is the best power source for the Hi End. However, it is really difficult to provide pure DC for high watt power amplifier as the huge capacitor (battery) size or large power capacity demanding.
The power voltage and current supply is very important for operating the power amp which could affect the sonic performance directly.
The output stage of a power amplifier during peak power operation will draw on instantaneous high current from the DC voltage rails. As the DC voltage is supplied by the rectifier triodes, which convert AC to DC, and the filtering capacitors, which smoothen out the rippling voltage and also act as the reservoir, the performance of the power supply largely depends on the capacity of these components. When the output power of the amp is relatively low, the demand on the current is small and steady, the supply will be stable and will not deteriorate. When the output power is relatively high, more DC current will be drawn from the capacitors, putting a strain on the rectifier triodes and causing AC ripple voltage. When a ripple voltage exists, it will cut short the recharging time of the capacitors and develop a 120Hz pulse noise that in turn interfere the output stage transistors, inducing distortion within the audible frequencies. The best solution to overcome this is by adopting a power supply capable of extremely large current (probably 5 to 10 times of what is required to meet normal demand) and very large capacitor(s) to sustain the supply. Under such circumstances, a reliable battery power supply can fulfill the dual role of large current and large capacitor.
The battery power supply could provide the flow current with the huge power volume. SLAP is using YUASA NP7-12 (12V/7AH) sealed lead-acid battery which maximum output is 105A w/o pulse noise. For under 20Watt output Class T or Class D amplifier which is much over its DC requirement.
Is there any further reason to choose battery power?
There is another reason to choose the battery power instead of linear power to seclude the AC power interruption. During the path of AC power source transfer from power planet through the high-voltage power transfer to substation needs to be boost & depress the voltage, it takes all different interruption and noise( i.e. radio wave, electromagnetic wave, high tension noise comes from all kinds of automobiles spark plug lighting, all motors working noise) to your Audio equipment. Even if your AC power is pass the AC LINEFILTER to strain the noise, the AC power source still could be one possible noise source
SLAP battery power supply unit will be the best solution for fully isolated power source from AC environment as the internal AC power is only for charging stage. The AC power source will be totally isolated one switching button by the main power control board.
Is there any further particular accommodating design?
SLAP has interior auto charging/ discharging power managing design. It could auto-detect the battery voltage and auto-adjust the charging current by itself which could protect the battery have no chance to over-charge or over-heat to decrease the battery life. For discharging protection, we design the low voltage detective circuit while the voltage under 10.5V it will cut the output automatically which protect the battery won’t decrease its life and the enable loading problem.
The button setting is very simply and friendly, users only need to press the button then all the process could be monitoring very easily. All charging and discharging status are shown by one double color LED light, it very easy way to operating the SLAP.
Key Feature
SLAP is designed with automatic monitoring by TI UC3906IC which is a SLA battery charger controller.
- It is using 3 stage charging management to prevent overcharging and this design could extend the life of SLA battery.
- Front panel dual color LED indicator for monitoring power status-The LED indicator of front panel could show all charging and discharging stage at PSU on mode. The front LED indicator could start monitoring the charging stage. If the "PSU OFF", the charging process is still working but it cannot be show the monitoring status through the LED as it won't light
- Internal wiring use AWG18 copper wires.
- DC output terminal use 3 pin XLR connector made by USA CONTECH the maximum current capability is 6 amps.
- AC input fuse and DC output fuse for safety consideration.
- Battery Low Voltage monitoring circuit ensure extension battery life when low battery (10.5V DC), cut out the SLAP output which could protection the battery do not over-discharged
Appearance
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The cabinet is of a rigid construction with elegantly appearance by the size185*146*156mm with 6mm thick aluminum face plate .The stylish design with the stable setting and frame will bring fun for life. It also contributes to the touch and fell factor and is essential for the long lasting life even in a tough environment. All the components used in SLAP are of the highest quality and have been selected through intensive listing sessions from the material itself.
Specification
Rated input voltage |
AC 90~260V, 47~67Hz |
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Battery type |
12 volt nominal SLA |
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Battery size |
12V/7Ah |
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Charging current |
80mA~ 750mA |
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Charging type |
Lead Acid Chemistry |
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Charging current |
Constant current/ constant voltage/float |
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Stage 1: current 750mA |
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Stage 2: current 400mA |
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Stage 3: float charge current 200~400mA |
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“Charged” light turns on and float charge starts when the charge current is approx 80mA when the battery charge voltage is above 14 volts. |
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Weight |
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Cooling |
Natural convection, no fan |
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Protections |
AC input fuse, DC output fuse |
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MTBF |
30,000 hours by MIL-STD calculation |
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LED Indications |
Charging |
Red |
Charged |
Green |
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In use |
Green |
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Battery low |
Red & green blinking |
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