Soft Start For Torch – Increases The Life Of Torch Bulbs

The halogen or krypton bulbs in modern torches (USA
and Canada: flashlights) have a limited life and are not particularly
cheap. A simple modification in the torch lengthens the life
appreciably. It is a fact of nature that any incandescent bulb has a
finite life. However, the bulbs in modern torches (US and Canada:
flashlight) have a less-than-average life. The reason for this is that
the halogen or krypton bulbs used are operated at over-voltage to give
as bright a light as feasible. The life of these bulbs may be extended
红包扫雷苹果下载地址 simply by connecting a resistor in series with the bulb.

For instance, when the battery voltage is 6V and the bulb is a 500mA
type, a series resistor of 1Ω will reduce the voltage across the bulb
by about 0.5V. This will certainly lengthen the life of the bulb, but it
will also cause a reduction in the available brightness. Also, energy
is wasted in the resistor (evinced by heat production). Clearly, this is
not a very good solution to the problem. A better one is shunting the
bulb with a transistor in series with a resistor.

MOSFET:

Another well-known fact is that incandescent bulbs normally burn out
when they are being switched on. This is because the resistance of the
cold filament is significantly lower than that during normal operation.
This results in a switch-on current that is much higher than the normal
operating current. Clearly, much is to be gained by damping the
switch-on current. The switch-on current may be limited by a simple
circuit that is small enough to allow it to be built into most types of
torch. As the diagram shows, such a circuit consists of nothing more
than a metal-on-silicon-field-effect-transistor, or MOSFET红包扫雷苹果下载地址, and a resistor.

The transistor may be almost any current n-channel type that can
handle the requisite power. The popular BUZ11 or BUZ10 is eminently
suitable for the present application. The requisite limiting of the
start-up current is provided by the internal gate capacitance of the
transistor in conjunction with the large gate resistor. If needed, a
small capacitor may be added between gate and drain. Once the transistor
is conducting hard, the remaining losses are negligible. This is true
also when the torch is switched off: the quiescent current flowing
through the transistor is much smaller than that caused by the
红包扫雷苹果下载地址 self-discharge of the batteries.

Finally:

Since it is much simpler to break into the positive supply line of a
torch than into the negative line, the addition of the limiting circuit
makes it necessary for the batteries to be inserted into the torch the
other way around from normal (as indicated by the manufacturer). Also,
the on/off switch of a modified torch works the other way around from
normal. Fitting the modification in some of the popular Mag-Lite torches
is fairly straightforward.

After the rubber cover of the on/off switch has been removed, the
entire push-button switch mechanism may be removed by releasing a
central hexagonal bolt. The switch terminals may serve as soldering
supports for the transistor-resistor series network. If it proves
impossible to obtain a 47 MΩ resistor, four or five
surfacemount-technology (SMT) resistors of 10 MΩ may be linked in series. Such a link works just as well and is almost as small as a normal 47MΩ resistor.

Battery Overvoltage Protection IC

Battery Overvoltage Protection IC

Battery Overvoltage Protection IC

the bq2946xy family of products is a secondary level voltage monitor and protector for li-ion battery pack systems. the cell is monitored for over voltage condition and triggers an internal counter once the ovp threshold is exceeded and after a fixed set delay the out is transitioned to a high level. the output is reset (goes low) if the cell voltage drops below the set threshold minus the hysteresis.

Device Uses
  • 2nd-Level Protection in Li-Ion Battery Packs in:
    • Tablets
    • Slates
    • Portable Equipment and Instrumentation
Features
  • Single-Cell Monitor for Secondary Protection
  • Fixed Programmable Delay Timer
  • Fixed OVP Threshold
    • bq294602 = 4.35 V with 4-s Delay Timer
    • bq294622 = 4.45 V with 4-s Delay Timer
    • bq294682 = 4.225 V with 4-s Delay Timer
    • bq294604 = 4.35 V with 6.5-s Delay Timer
    • bq294624 = 4.45 V with 6.5-s Delay Timer
    • bq294684 = 4.225 V with 6.5-s Delay Timer
  • High-Accuracy Overvoltage Protection:
    ± 10 mV
  • Low Power Consumption ICC ≈ 1 µA

    (VCELL < VPROTECT)

  • Low leakage current per cell input < 100 nA
  • Small package footprint
    • 6-pin SON

Li-Ion Battery Switching Charger

Li-Ion Battery Switching Charger

Li Ion Battery Switching Charger

as mobile devices become increasingly power-hungry, battery sizes have been forced to increase in capacity in order to meet the demand for longer usage time. designers are faced with the challenge of decreasing the amount of time it takes to charge these larger batteries, minimizing the thermal dissipation created during charging, and supporting enhanced features such as usb-otg host capabilities.

working with customers to address these challenges, fairchild semiconductor , a leading global supplier of high performance power and mobile products, developed the fan5401x family of usb – compliant, li-ion switching chargers with full usb on – the – go (usb-otg) support. building on the switch – mode topology fan5400 family, the first device in the family, the fan54013 offers increased max charge current of 1.45a and increased usb otg boost power that can support a full 500ma at 5v.

红包扫雷苹果下载地址when charging a single-cell or parallel-cell lithium ion (li-ion) battery through a usb port or ac/dc adaptor, the switch-mode based topology of the fan54013 provides faster charge times and overcomes the thermal issues associated with linear charger solutions in use today. typical applications include single-cell or parallel-cell li-ion battery charging in devices such as cell phones, smartphones, tablets, wireless broadband hotspots, digital cameras, portable media/game players and other portable products.

红包扫雷苹果下载地址in addition to providing up to 94 percent charging efficiency, the fan54013 delivers a suite of protection features such as integrated 20v input voltage rating, thermal protection, reverse current blocking, watchdog timers, and +/-5 percent accurate input current limiting for usb compliance. usb otg hosting is supported with an integrated 5v 500ma boost that uses the same inductor as the charger thereby reducing external component count.

for flexibility the fan54013 charging parameters and operating modes are programmable through an i2c interface, which operates up to 3.4mbps. available in a 1.96 × 1.87mm, 20-bump, 0.4mm pitch csp package, the fan5401x family is the smallest switch-mode solution on the market that provides both charger and full 500ma usb-otg 5v boost functionality.

红包扫雷苹果下载地址fairchild’s usb expertise, combined with its broad portfolio of mobile power solutions, allows designers to innovate and differentiate their mobile offerings. by working with customers, as well as by identifying developing trends in the marketplace, fairchild continues to develop the right power management solutions that advance mobile designs and enrich the user experience.

红包扫雷苹果下载地址price (each, 1k pcs.): fan54013 = $1.27

availability: samples available upon request

delivery: 8 to12 weeks aro

2003 Peugeot 306 Under Dash Fuse Box Diagram

2003 Peugeot 306 Under Dash Fuse Box

2003 Peugeot 306 Under Dash Fuse Box Diagram

2003 Peugeot 306 Under Dash Fuse Box Map

2003 Peugeot 306 Under Dash Fuse Box Map

Fuse Panel Layout Diagram Parts: brake pedal position, data link connector, electronic control unit, fuseible link, hydraulic modulator, ignition switch, instrument panel, pump motor, pump motor relay, wheel speed sensor, ABS warning lamps, battery.

1998 Infinity Q.45 Engine Fuse Box Diagram

1998 Infinity Q.45 Engine Fuse Box

1998 Infinity Q.45 Engine Fuse Box Diagram

1998 Infinity Q.45 Engine Fuse Box Map

1998 Infinity Q.45 Engine Fuse Box Map

Fuse Panel Layout Diagram Parts: 红包扫雷苹果下载地址ASCD actuator, daytime light cancel relay, wiper amplifier, fusible link and relay box, cooling fan, starter relay, wiper motor, actuator, battery, daytime light, power transistor, power transistor unit, headlamp relay.

2002 GMC Envoy Rear Underseat Fuse Box Diagram

2002 GMC Envoy Rear Underseat Fuse Box

2002 GMC Envoy Rear Underseat Fuse Box Diagram

2002 GMC Envoy Rear Underseat Fuse Box Map

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Fuse Panel Layout Diagram Parts: Right Rear Parking Lamps, Lock, Left Rear Parking Lamps, Auxiliary Power, Left Turn Signal, Radio, TR PARK, Right Turn Signal, Rear Fog Lamps, Door Control Module, Fog Lamps, Power Seats, Blank, Rear Climate Controls, Front Wipers, STOP, Front Parking Lamps, Ignition, Four-Wheel Drive, Brakes, Sunroof, Battery , Rain sense Wipers, Parking Lamps.

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2004 Pontiac Aztek Fuse Box

2004 Pontiac Aztek Fuse Box Diagram

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Fuse Panel Layout Diagram Parts: PCM relay, ABS system, trans solenoid, fuel injection, low beam, high beam, park lamps, air pump, ignition main, cruise control, ABS system, cooling fan, battery, fuel pump, A/C cluster, engine control.

1994 Buick Century Front View Fuse Box Diagram

1994 Buick Century Front View Fuse Box

1994 Buick Century Front View Fuse Box Diagram

1994 Buick Century Front View Fuse Box Map

1994 Buick Century Front View Fuse Box Map

Fuse Panel Layout Diagram Parts: hazard stop, courtesy lamp, power accu, cigar lighter, power control module, injector, ignition coil, fan, alternator fan, air bag, tail light, heater, gauges, power window, ignition switch, wiper, radio, battery,