Author Archive

New Contemporary Funny Car Body Kits

Many kit bodies to choose from.  Just add your chassis and… drag race.
H.O.D.R.A. Approved.

Categories: Reference

Secrets of the Pancake Commutator Plate

September 18, 2009 Leave a comment


Last month we shared a conversation with you all regarding the certain evolution  in the “next generation” of  pancake armatures  (rotors & plates) with winding guru Daniel Cardinale.  Dan has developed a new generation of commutator plates. This technology dosn’t come without research and development.  Looking at the past can assist with developing the future….so here is a summary of the analysis of the great ones (and not so great ones)  from the past.


  * LaGanke Silver Comm plate – this is actually a good quality nickel
     plating over copper.  Fairly common in the PCB world.
   * Model Motoring Silver Comm plate – this is a poor quality nickel
     plating over copper.  Very porous.
   * JL Silver Comm plate – this is a silver immersion coating over
     copper.  Typical on PCB’s.  Used to prevent copper tarnishing
     after soldering.  Useless coating in our application.
   * Original Aurora Silver Comm plate – this is the closest to real
     silver plating over copper.  Also why it wore off fast.


What’s next for 2010 and the future of pancake drag racing?   Stay tuned for a full  H.O.D.R.A. report.

Categories: Reference

In Memoriam – Truly TOP s!

September 14, 2009 Leave a comment


   Tom was a mentor in realistic vacuum forming. He taught me many intricacies of
the art form in my quest to obtain and provide greater detail from what some
otherwise would call “blobs”. Tom was a great modeler, mentor and friend. I lost
track of him about three years ago. I am very sorry to hear of his passing and
my condolences go out to his family and friends. A true gentleman competitor in
the hobby sport. He will be missed. (and so too his talent).  Truly TOP  s !

Without his guidance and influence, RJM Racing HO Customs – Flaming Shark Drag Bodies – would not have come into existence.

Categories: Reference

DC HO Motors Skunk Works – New Design Commutator Plates for Pancake Motors

September 7, 2009 1 comment

Word in the pits is that Daniel of  DC HO Motors is developing  new  commutator plates for  pancake motors  with a much improved design .  This new design and material is slated to put pancake motor drag racing in new league and a new set of record books.  More will be posted as press is released.  Is genuine  metal in your drag racing  future?   I had the pleasure of   “in person” chatting with Daniel in April of this year and have exchanged several emails regarding this topic…and product.

Categories: Reference

Staff of the H.O.D.R.A.



hodra-pancake-motor-technical-advisor - Daniel




Here is our voluntary comittee staff.   Enjoy !

Categories: Reference Tags:

2009 H.O.D.R.A. Grand Nationals

February 22, 2009 Leave a comment


With deepest regrets, the 2009 H.O.D.R.A. Grand National event is cancelled due to  scheduled surgery on part of one of the organizers.

We apologize for any inconvenience this may cause.



NOVEMBER 7th, 2009  -cancelled event

Categories: Reference

Power Supply Glossary

February 22, 2009 Leave a comment

Many enthusiasts are beginning to move away from batteries and chargers

 to fully regulated power supplies.This glossary will assist you in understanding what it means and how it works.


Ambient temperature
the temperature of the still air surrounding a power supply, measured a minimum of 4 inches (10.2 cm) from the supply. Note that Martek Power Abbott power supplies are conduction-cooled and that temperature specifications refer to baseplate temperature, not ambient temperature.

Baseplate temperature
the temperature at the hottest spot on the baseplate of the supply, usually at the center, but measurements of the hottest spots at the edges are valid approximations.

the condition created during peak usuage periods when electric utility companies intentionally reduce their line voltage by approximately 10 – 15% to counter excessive demand.

Common-mode noise
the component of noise in a power supply that is common to both the dc output and return lines with respect to the source power return point (input neutral).

in a multiple output power supply, the voltage change at one output caused by the load change on another, expressed as a percentage of the nominal voltage.

a type of overvoltage protection that rapidly places a low resistance shunt (typically an SCR) across the power supply output terminals when the output voltage exceeds a predetermined value.

[Click] on image to see a larger version.

reducing one operating parameter to compensate for changes in other parameters to maintain reliability. For example, the reduction in output power at elevated temperatures.

Differential-mode noise
the component of noise in a power supply, excluding common-mode noise, that is measured between the dc output and output return.

the ratio of total output power to input power, expressed as a percentage. Efficiency must be specified at a specific combination of load and input voltage.

Electromagnetic interference (EMI)
unwanted high-frequency energy that is conducted through the input or output lines or radiated into space by switching power supplies. Also known as radio-frequency interference (RFI).

Foldback current limiting
a type of power supply overload protection that decreases the output current as the overload increases, until the current reaches a minimal value at short-circuit. Foldback current limiting minimizes internal power dissipation under overload.

Forward converter
a power supply switching circuit that transfers energy to the transformer secondary when the switching transistor is on. Forward converter circuits store minimal energy in the transformer.

Ground loop
a condition that causes unwanted feedback when two or more circuits share a common electrical return or ground lines.

Holdup time
the time during which a power supply’s output voltage remains within specified limits following the loss or removal of input power. Holdup time is normally measured at full load and nominal line conditions.

Input voltage range
the range of input voltage values for which a power supply or dc-ac converter operates within specified limits.

Inrush current
the peak instantaneous input current drawn by a power supply when it is initially turned on.

Inrush circuit limiting
a circuit that limits the inrush current when a power supply is turned on.

Insulation resistance
the dc resistance between two defined points at a specific voltage in a controlled environment (25°C temperature and less than 50% relative humidity).

a device that changes dc power at its input into ac power at its output. Also called a power converter.

the electrical separation between the input and output of a power supply due primarily to the power transformer. The isolation is a function of materials and spacings throughout the supply.

Isolation voltage
the maximum ac or dc voltage that may be continuously applied from input to output and/or chasis of a power supply.

Line regulation
the maximum change in output voltage, expressed as a percentage, that occurs as the input voltage varies over its specified limits, with load and temperature constant.

Load regulation
the change in output voltage, expressed as a percentage of nominal voltage, that occurs as the load changes from minimum to maximum, at constant line and constant temperature. Load change may be specified for other than no load to full load as, for example, 50% load to full load.

Local sensing
using the power supply output voltage terminals as the error-sensing points to provide feedback to a voltage regulator.

Mean time between failure (MTBF)
the failure rate of a power supply, expressed in hours, either predicted as prescribed by Military Standard MIL-HDBK-217 or measured as prescribed by Military Standard MIL-STD-781C.

Operating temperature range
the range of ambient or case temperatures through which a power supply may operate safely and perform within specified limits. For Abbott military power supplies, this range refers to baseplate temperature.

Output current limiting
a protective feature that keeps the output current of a power supply within predetermined limits during overload to prevent damage to the supply or the load. The supply automatically returns to normal operation following the removal of the overload.

Overload protection
a protective feature that limits the output current of a power supply under overload conditions so that it will not be damaged.

Overvoltage protection (OVP)
a protective feature that shuts down a power supply (reduces the output voltage to a minimal level) to prevent damage to the load when the output voltage exceeds a predetermined limit.

Parallel operation
the connection of the outputs of two or more power supplies of the same output voltage to obtain a higher output current than either supply can provide alone. Parallel operation requires power supplies that are specifically designed to share the load.

Periodic and random deviation (PARD)
the unwanted periodic (ripple) or aperiodic (noise) deviation of the power supply output voltage from its nominal value. Ripple is a function of the input line and switching components. PARD is expressed in minivolts peak-to-peak or rms, at a specified bandwidth.

Pulse-width modulation (PWM)
a method of regulating the output voltage of a switching power supply by varying the width, but not the height, of a train of pulses that drives a power switch.

Rated output current
the maximum load current that a power supply is designed to provide at a specified ambient temperature.

the power supply circuit that controls or stabilizes the output voltage at a preset value.

Remote sensing
a technique for regulating the output voltage of a power supply at the load by connecting the regulator error-sensing leads directly to the load. Remote sensing compensates for voltage drops in the load leads.

for an adjustabe supply, the smallest change in output voltage can be realized by an adjustment.

Reverse voltage protection
a feature that protects a power supply from damage caused by a voltage of reverse polarity applied at the input or output terminals.

Ripple and noise
(see Periodic and random deviation)

Series regulation
a popular method of linear regulation in which the control device is connected in series with the raw dc and the load to achieve constant voltage across the load.

Short-circuit protection
a protective feature that limits the output current of a power supply to prevent damage to the supply caused by short circuits.

Soft start
a feature that ensures the smooth, controlled rise of the output voltage. This feature protects the switching transistors from transients when the power supply is turned on.

Storage temperature
the range of ambient temperatures through which an inoperative power supply can remain in storage without degrading is subsequent operation.

Switching frequency
the rate at which the dc voltage is switched in a dc-dc converter or switching power supply.

Switching regulator
a high-efficiency switching circuit that operates in a closed loop system to regulate the voltage across a load, generally by means of a pulse-width modulator.

Temperature coefficient
the average change in output voltage per change in degree of a baseplate temperature, expressed as a percentage of nomimal output voltage, over a specified temperature range.

Thermal protection
a protective feature that shuts down a power supply if its internal temperature exceeds a predetermined limit.

a characteristic of a multiple-output power supply that describes the changes in the voltage of one output with respect to changes in the voltage or load of another.

Transient recovery time
the time required for the output voltage of a power supply to settle within specified output accuracy limits following a step change in output load current or input voltage.

Warm-up time
the time required after a power supply is initially turned on before it operates according to specified performance limits.




AC Input Voltage – The nominal range on the power supply label as approved by the safety agency is always 10% less than the usable input voltage range.  For example, a switching power supply with a nominal 100 to 240VAC has an actual range of 90 to 264VAC. Our data sheet shows the usable voltage range; the label will show the safety agency rating. AC Input Frequency – The nominal range of 47 to 63 Hz is important in linear power supplies, but most switchers are insensitive to input frequency and can operate from DC to 400Hz. This is especially important in countries where the power may be of poor quality.

AC Input Current – The current drawn under the maximum DC load. Safety agencies require this be marked on the label.

AC Inrush Current – The instantaneous current drawn when the power supply is turned on cold. Larger power supplies generally incorporate a thermistor to limit this amount. It is most important in considering an AC switch rating.

Cross Regulation – On a multiple output power supply, the effect on some outputs while varying the load on other outputs. Our standard is to hold the constant loads at 60% of full load, while varying the measured output from 20 to 100% (of rated load). NOTE: The effect may be extreme if the highest current output is fully loaded, and a quasi-regulated output is lightly or not loaded. A preload may be required if you have this condition in your system.

DC Output Voltage – The nominal voltage setting.  In adaptors, this voltage is preset. With open frame power supplies, a voltage adjust potentiometer is standard. The adjustable range is usually 5%.

Efficiency – Output power divided by Input Power. This will vary depending on the load and AC  input voltage. Values shown are usually nominal at rated voltage and load.

Emissions – Electromagnetic radiation emitted into the atmosphere from the power supply. Conducted is that energy sent down the AC line cord; radiated is sent into the air. Adaptors must meet both but many open frame switchers are only rated for conducted (the assumption being that they will be placed into the customer’s box).

Hipot (Dielectric Withstand) – The test voltage between the input and output, and output to ground.  See our safety compliance section.

Hold-up Time – Determined by the storage factor within the power supply.  In linear supplies, the time output fails when AC input fails, is almost immediate. In switching power supplies, energy is stored in the bulk (input electrolytic) capacitor providing a useable hold up time to protect against transient power outages. Since this is highly proportional to AC voltage and DC load, it is given under specified conditions.  High AC voltage and low DC loads provide the best conditions.

Immunity – Testing done to determine immunity from electromagnetic or electro static discharge (ESD). The European IEC 801 or 1000 or EN61000 are test specifications and procedures.  Dash numbers indicates the levels.  Generally, the higher the number, the better the power supply is able to withstand the test condition.

Leakage Current – See our safety compliance section

Line Regulation – The change in DC output voltage when the AC input voltage is varied through out its range while the DC load is held constant.  In switchers, this can be 90 to 264 volts AC unless otherwise specified.  In linears, it may be as limited to 108 to 132 volts AC.

Load Regulation – The change in DC output voltage when the DC load is varied.  Unless otherwise specified, the range is minimum load to full load.  The AC voltage is held at nominal during this test.

Line and Load Regulation – The combined effect of varying the DC load and AC input voltage; the worse case condition.

Minimum Load – Some switching power supplies require a minimum load to stay within their specifications. However, operating them unloaded does no damage.

Maximum Load – The load specified for continuous operation. This will be the load used for safety applications.

MTBF – Mean time between failures was a term adopted by the military and elaborated on in MIL-HDBK-217, which provides values for capacitors, resistors, etc.  An alternate standard was developed by Bell Labs (Bellcore).

Over current Protection – Modern power supplies are almost always provided with some form of short circuit protection. 

Over voltage Protection – More important in linears, where failure of a pass transistor could easily put excess voltage on IC’s. With switchers, most failures cause no output at all.

Operation Temperature – The ambient temperature conditions under which the supply was designed to operate at full load. Most power supplies can operate at higher ambient if the output load is properly derated.

Peak Loading – For transient conditions only (such as disk drive start up).  The power supply may not remain within specified regulation during the peak condition.  The amount of time this load can be applied (duty cycle) varies greatly from design to design. It’s best to consult the factory with your load profile.

Ripple – The AC component superimposed over the DC output voltage. In linear power supplies, this is the traditional “hum” at 60 or 120 hertz. In switching power supplies, it is a complex waveform.  Although traditionally spec’d at 1%, it is often much lower. Ripple can increase at maximum loading and minimum input voltage.

Switching Frequency – Term used by switchers only. Many switching power supplies operate at a fixed frequency; some use variable frequency designs. 






Categories: Reference

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