Arachnid Labs Re:load Pro User manual

User Manual
Arachnid Labs
Re:load Pro
Copyright 2014, Arachnid Labs
Licensed CC-BY-SA http://www.arachnidlabs.com/reload-pro/

Arachnid Labs
2
Re:load Pro User Manual
EC Declaration of Conformity
In accordance with EN ISO 17050-1:2004
We Arachnid Labs Limited
of 183 Richmond Road, E11 4DA, UNITED KINGDOM
in accordance with the following directive(s):
2004/108/EEC The Electromagnetic Compatibility Directive
2001/95/EC The General Product Safety Directive
hereby declare that:
Equipment Re:load Pro DC Active Load
is in conformity with the applicable requirements of the following docu-
ments
Ref Title
EN 61326-1:2013 Electrical equipment for measurement, control
and laboratory use. EMC requirements. General
requirements.
EN 61010-1:2010 Safety requirements for electrical equipment for
measurement, control, and laboratory use. Gen-
eral requirements.
I hereby declare that the equipment named above has been designed to
comply with the relevant sections of the above referenced specications.
The unit complies with all applicable Essential Requirements of the Direc-
tives.
Signed,
Name: Nicholas Johnson
Position: Director
Done at: London, UK
On 2013-09-06

Arachnid Labs
3
Re:load Pro User Manual
Safety Notices
Review the following safety precautions carefully before operating this de-
vice to avoid personal injury or damage to the device and any products
connected to it. To avoid potential hazards use the device as specied by
this user’s guide only.
This instrument should be serviced only as described in this manual.
To Avoid Fire or Personal Injury
Observe All Terminal Ratings To avoid re or shock hazard, observe all
ratings and marks on the instrument. Follow the user’s guide for further
ratings information before making connections to the instrument.
Do Not Operate Without Covers Do not operate the instrument with cov-
ers or panels removed.
Avoid Circuit or Wire Exposure Do not touch exposed connections and
components when dangerous voltages are present.
Do Not Operate With Suspected Failures If suspected damage occurs
with the instrument, have it inspected by qualied service personnel be-
fore further operations.
Provide Proper Ventilation Refer to the installation instructions for prop-
er ventilation of the instrument.
Do not operate in wet/damp conditions
Do not operate in an explosive atmosphere
Keep product surfaces clean and dry
Measurement Category The Re:load Pro is intended to be used for
measurements in Measurement Category I.

Arachnid Labs
4
Re:load Pro User Manual
1. Overview
The Arachnid Labs Re:load Pro is a versatile and robust constant cur-
rent active load intended for testing power supplies, batteries, and other
current-supplying electronic equipment. It can also be used for other ap-
plications in which excellent current regulation is required, such as elec-
troplating.
Features of the Re:load Pro:
• Active load with real-time analog current feedback loop.
• Dissipates 25 watts continuously, or more for short periods.
• Handle up to 6 amps, and 0-60 volts.
• Easy to use and intuitive user-interface.
• Current adjustable with milliamp precision over the whole range.
• Protection against overcurrent, overvoltage, overtemperature, ESD
and reverse polarity.
• Power supplied over USB from either a computer or a USB charger.
• Fully isolated USB interface. Your computer is isolated from any
direct interaction with dangerous voltages and currents.
• Fully controllable over USB, with monitoring functionality.
• Congurable display, showing voltage, current, power, resistance,
and total energy dissipated.
• Open Source, with a USB bootloader, so rmware can be modied
and upgraded without expensive development tools.
The Re:load Pro was made possible by the generous support of 361 back-
ers on Kickstarter.
2. Calibration
Before initial use, calibrate the Re:load Pro. The calibration procedure re-
quires test leads, a power supply capable of supplying at least 2 amps DC,
and a current meter, either integrated into the PSU or discrete.
1. Detach all test leads.
2. Press in the knob to display the menu. Rotate the knob clockwise until
‘Calibration’ is selected. Press the knob again to select Calibration
mode.
3. The display will show “Remove Leads”. Press in the knob to perform

Arachnid Labs
5
Re:load Pro User Manual
offset correction.
4. Attach a power supply using test leads. The power supply may be
congured for any voltage between 1V and 60V, but 9.99V is recom-
mended for best calibration accuracy. If the power supply is equipped
with current limiting, the limit must be set to at least 2 A. If the PSU
lacks an integrated current meter, attach a current meter between the
Re:load Pro and PSU.
5. A voltage measurement will be displayed. Rotate the knob until the
measured voltage matches the actual voltage supplied by the PSU.
Press the knob.
6. The Re:load Pro now attempts to draw approximately 2 amps from the
power supply. Rotate the knob until the current measurement matches
the actual draw as measured by the current meter. Press the knob.
7. The Re:load Pro now performs internal calibration operations. Once
this is complete, the main screen is again displayed, and calibration
is complete.
3. General Usage
1. Attach a USB cable between the Re:load Pro and a computer or USB
power source. The Re:load Pro will boot up and display the splash
screen. After 3 seconds, this will clear to display the readouts.
2. Rotate the knob on the right side until the main display shows the
desired current draw.
3. Attach test leads between the red and black (positive and negative)
terminals and the device under test (DUT), such that a circuit is formed
with the Re:load Pro in series with the DUT and a power source.
4. Energise the power source; the Re:load Pro will automatically adjust
its resistance so that the specied amount of current is consumed.
The bottom left and right readouts show the actual current draw and
measured voltage, respectively.
At any time during operation, you may adjust the current consumption by
turning the knob to select the appropriate value.
When under load, the Re:load Pro can generate a lot of heat. Ensure the
heatsink at the back remains unobstructed and well ventilated for safe and
effective operation.
The Re:load Pro is equipped with an overtemperature cutout that will pre-

Arachnid Labs
6
Re:load Pro User Manual
vent damage to the device in case of overtemperature. If this engages, the
Re:load Pro will set its current limit to 0, and display a message indicating
an overtemperature condition. Pressing enter dismisses the message and
allows you to resume using the device as normal.
4. Display Conguration
The main display is congurable to show a variety of different measure-
ments as needed for the task at hand. The readouts can be recongured
at any time from the menu, and are stored persistently.
To change a readout:
1. Press the knob to enter the menu.
2. Select “Readouts” and press the knob.
3. Select which reaout to change - the main (large) readout, the lower
left, or the lower right. Press the knob to select.
4. Select the desired measurement and press the knob. The selected
readout is replaced with the selected measurement.
5. USB Control & Monitoring
The Re:load Pro comes equipped with a USB serial interface, providing
the ability to control and monitor it from a connected computer. Serial set-
tings of 115200/8/N/1 should be used. Complete documentation of the
serial protocol is out of scope for this manual; consult http://www.arachnid-
labs.com/reload-pro/usb-interface.html for more details.
6. Firmware Updates
The Re:load Pro ships with a bootloader that allows updating of rmware
over USB. Updating the rmware rst requires entering bootloader mode,
which can be accomplished in two ways.
If the standard rmware is running, enter the menu and select “rmware
update” to enter rmware update mode.
If the standard rmware is not functional, enter recovery mode by unplug-
ging the device, and plugging it into a computer while holding in the knob.

Arachnid Labs
7
Re:load Pro User Manual
The display will turn on but remain blank; you may then release the knob.
After entering bootloader mode, use the bootloader host software on your
computer to send updated rmware to the device.
7. Factory Reset
Should user data become corrupted or invalid, it may be necessary to
perform a factory reset.
To perform a factory reset, plug the Re:load Pro into a USB power source
or computer, and wait for the splashscreen to display. As soon as it does,
press the knob in, and hold it until the main display is shown.
This will cause all data to be reset to factory settings, including calibration
data. Follow the steps in section 2 to re-calibrate the device.
8. Disassembly & Servicing
Should you need to disassemble the Re:load Pro, care is required in order
to avoid damaging sensitive connectors inside the device.
1. Use a small at-head screwdriver to loosen the grub screw on the
knob. Remove the knob and set it aside.
2. Using a phillips head screwdriver, unscrew the four front panel screws.
Gently pull the front panel away from the enclosure. It is connected by
three spade terminals and one ribbon connector.
3. To disconnect the ribbon connector, identify the socket on the PCB. It
has a small black tab on either side of the ribbon cable. Use ngers or
a tool to gently pull this tab towards you in order to unlock the ribbon
cable. Pull gently on the ribbon cable to remove it from the socket.
4. Disconnect the spade connectors from the banana jacks by grabbing
the connector by its plastic housing and pulling while securely holding
the front panel in your other hand. Do not pull on the wire to remove
the spade connector. Set aside the front panel.
5. Unscrew the four screws connecting the heatsink to the enclosure.
Gently slide the heatsink and enclosure apart; the PCB will remain
attached to the heatsink. Take care not to put any stress on the com-
ponent attached to both the heatsink and the PCB.

Arachnid Labs
8
Re:load Pro User Manual
Specications
DC
Input Voltage Range 0 ~ 60 VDC
Maximum Current 6 A
Maximum Power Continuous 25W
Peak 50W for 10 min
75W for 1 min
Measurement Accuracy 2mA/10mV (after calibration)
Output Accuracy 2mA (after calibration)
AC
Input transient response time 20 μs @ 12V - 5V burden voltage
transient
Frequency Response 50 Khz (computed)
Power
Supply Voltage (USB) 4.5 - 5.5 VDC
Power Consumption Less than 5W
Environmental
Ambient Temperature Operating 10°C ~ 40°C
Non-operating -20°C ~ +60°C
Cooling Natural Convection
Humidity ≤90% Relative Humidity
Altitude Operating 3,000m or below
Non-operating 15,000m or below
Mechanical
Size Width 112mm
Height 59mm
Depth 120mm
Weight 510g