Dynamax AVRD 3.2 User manual

AVRD version 3.2
Voltage Regulator
Installation and Operation
Manual
10808 Fallstone Road #350
Houston, TX 77099, USA
Tel: [phone] Fax: [phone]
Toll Free: 800-896-7108
[email protected] dynamax.com

TABLE OF CONTENTS
1.0 Introduction to AVRD .................................................................................................. 2
1.1 AVRD System Features ................................................................................................ 3
1.2 Unpacking, Bill of materials........................................................................................... 4
1.2.1 Bill of materials.................................................................................................................................. 4
1.3 Specications ................................................................................................................ 4
2.0 Installation & Operation.............................................................................................. 5
2.1 Installation .................................................................................................................... 5
2.1.1 List of Tools required to install AVRD ................................................................................................ 5
2.1.2 Assembly Steps ................................................................................................................................ 6
2.2 Power sources .............................................................................................................. 7
2.3 Operation .................................................................................................................... 7
3.0 AVRD Applications...................................................................................................... 8
4.0 Safety and Maintenance ............................................................................................. 9
5.0 Warranty .................................................................................................................... 10
Copyright 2005, Dynamax Inc
All Rights Reserved
This manual refers to AVRD ver. 3.1, Dual adjustable voltage regulator.
Specications are subject to change. Dynagage is a new product for experimental
purposes under development. DYNAMAX Inc assumes no liability for customer assistance,
infringements of patents or copyrights arising from the use of this product. US Patents
covering the construction of various stem ow gauges are No 5,337,604 and 5,269,183.
DYNAMAX does not warrant or represent that any license, either express or implied, is
granted under any patent right, copyright, or other intellectual property right of DYNAMAX
relating to this product, or process. There are no implied warranties of merchantability or of
tness for a particular purpose given with the sale of any goods. DYNAMAX Inc shall not be
liable for consequential, incidental or special charges.
Dynagage, TDP, Dynamet, Flow32, Flow32W and Dynamax are trade marks of Dynamax
Inc PC208W PC400 and LoggerNet are trade marks of Campbell Scientic Inc.
Updated: 10/29/2008

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1.0 Introduction to AVRD
The adjustable - regulated power supplies in the electronics industry are seldom available
for eld applications, yet is possible to nd adjustable versions, which are good for small
labs and indoor application. In these cases the voltage regulation may be good, and the
voltage adjustment may be within the range, however if AC power is lost for a few moments,
again there is certainly a loss of data as well as false readings due to the heat lost during
a brownout. Thus the best eld solution is to have a battery charging source or solar panel
supplying current to a suitable battery, which in turn supplies the datalogger with a primary
(or backup) source of power, and then regulate the battery output to the sensors as needed.
In this application, the solar or battery charger source can vary signicantly, the battery has
a signicant reserve capacity, and yet the sensors power source is regulated and will not
uctuate.
The new AVRD is a dual adjustable voltage regulator for supplying excitation power to
sensor heater elements. This can be used as a general-purpose regulator for powering
dc systems or for exciting sensors with voltages in the range of 1-10 VDC and current not
exceeding 5A on each channel (10A combined). Refer to specications for more detailed
voltage and current parameters. New AVRD uses a Step-down switching controller with
external FET switch and frequency control, enabling the regulator to achieve higher current
and higher e󰀩ciency. In addition AVRD circuit is designed to dissipate the excess heat from
the switching with in the circuit thus eliminating the necessity of bulky heat sinks or cooling
systems. User can connect input source and the heater element s to the quick terminal
simply by inserting wire in the appropriate terminal slot and use screwdriver to secure the
wire properly. AVRD operates at a constant frequency of 330 KHz in the voltage range 2.5V
– 8.5V. This range being most commonly used excitation voltage for Dynamax sensors. A
constant frequency operation enables the AVRD to achieve better stability and higher input
output power e󰀩ciency.

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AVRD operates in discontinuous mode at lighter loads and switches to continuous mode at
higher loads thus achieving a higher e󰀩ciency of at least 80% for loads of 2W and increasing
e󰀩ciency at higher loads. The variation of e󰀩ciency with load current is shown below. Also
shown is the variation of e󰀩ciency with voltage at various load currents.
Chart on the right shows the linearity in the output
voltage and current at various resistive loads.
1.1 AVRD System Features
• General purpose adjustable voltage regulator
• High Current 5A on each output (a total of 10A)
• High E󰀩ciency of 91%
• Supply regulated DC output from unregulated DC input
• Output voltage adjustable using a 15-turn knob (each turn approximately 0.6V)
• Dual variable output voltages from a single AVRD
• SHDN signal to power OFF AVRD and the sensors at night to conserve power.
(output voltage when shutdown is 0V)
• In circuit over current latch protection
• Additional In-line fuse to protect from any over currents due to short circuit.
• Software power down from data logger
• Compatible to most sensors requiring DC excitation
• Compatible to Dynamax data loggers
• ON/OFF slide switch, LED indicator showing power ON
Wiring terminals, Control
knobs, ON/OFF switch
and LED
Base plate with
Mounting holes 6/32
size screws

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1.2 Unpacking, Bill of Materials
Using the following bill of materials, open the cartons and check o󰀨 the items to see that all
material was received in good condition. Notify Dynamax no later than 10 days after receipt
if there are any discrepancies. Notify the shipper and Dynamax immediately if goods are
damaged in transit by mishandling.
If AVRD is purchased as part of a data logger system, items in the BOM would be assembled
in to the logger and ready for operation. Other wise the items in BOM will be supplied as
mentioned below.
1.2.1 Bill of materials
1. AVRD - Dual High current, High e󰀩ciency voltage regulator
2. In-line fuse holder with fuse (5 mm x 20 mm, 15A)
3. Spare male (2 ea.) and female (2 ea.) quick disconnect spade terminals
4. Mounting kit
a. Screws (6/32-1/2”) – qty 2
b. Hex nut 6/32 - qty 4
Optional:
1. 12V/ 5Ahr battery
2. 12V/ 7Ahr battery
3. AC outlet adapter 15V / 4A
4. Solar Panel, 10W (MSX10), 30W (MSX30), 60W (MSX60) as per the sensor requirement
1.3 Specications
OUTPUT
Output voltage Range 1-10 V variable
Output current 5 A max. per channel
Output Control 15 turn precision potentiometers (~0.6
V/turn) ON/OFF switch; SHDN signal
Reference Voltage 0.8 V
No. of regulated outputs 2
No. of terminals per output 2
No. of terminal per output expandable to 6 (requires custom assembly at the factory)
E󰀩ciency 80% (3 V to 8 V)
90% (8 V - 10 V)
INPUT
Input voltage range 10-36 VDC
Minimum input voltage 10 V

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SHDN LINE (Power Down)
SHDN line input for power down <0.8 V
Output when shut down 0 V
SHDN line o󰀨 state (Normal/output ON) >0.8 V (or open circuit/no connection)
SHDN line drain current 1 mA
Temperature Specications
Operating Temp -40 to 85 C
Junction Temp 125 C (Tj=Ta+pd. 130 C/W)
Storage Temp -65 ro 150 C
Protection
Primary: Current limit In circuit current limit
Secondary: Fuse 15 A in-line fuse (5 x 20 mm)
Mechanical
Enclosure Aluminum, Anodized
Weight 1.5 lb (680 g)
Dimensions - Enclosure LxWxD 4-1/4” x 3-1/4” x 1-5/32”
108 x 83 x 29 mm
Dimensions - Overall 5-1/4” x 4-1/16” x 1-5/32”
133 x 103 x 29 mm
2.0 Installation and Operation
2.1 Installation
Provided that your system came with a regulator installed, there is nothing more to do but
skip to the next section on operation. Refer to data logger manual for operating instructions
specic to the logger. For custom, upgrades, or all other kits this section describes the tools,
recommended parts, and assembly.
2.1.1 List of Tools required to install AVRD
• 11/64” drill bit
• Electric drill
• Philips screw driver
• 5/16 Hex nut driver
• Wire cutter
• Wire stripper
• Flat blade screw driver
• Phillips head screwdriver
In addition required are wires for connecting AVRD input terminals to the power source (battery/
solar panel/ AC outlet adapter) and AVRD output terminals to the sensor heater elements.

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2.1.2 Assembly Steps
1) Assuming a panel mounting: (if not skip to #4)
2) Position AVRD vertically on the panel in a desired location
with terminals pointing up and mounting anges and holes on
the panel. As shown in the picture.
3) Mark the position of the two mounting holes on the panel
with a pencil marker.
4) Drill two small mounting holes in the marked locations using a 9/64” drill bit and electrical
drill. Smooth the drill edges using a le of sand paper.
5) Insert 6/32 – ½ “ screws (supplied with AVRD) from the bottom of the panel in the two
mounting holes. Secure these screws with hex nuts. Use thread lock to secure the screws
to the panel and upright.
6) Now place the AVRD in on the panel such that the two screws on the panel align and
slide into the AVRD mounting holes.
7) Once the unit is adjusted and aligned to be upright secure by using hex nuts on the screw
portion protruding out of the mounting holes.
8) Use thread lock to secure the screw threads from loosening.
9) Slide the ON/OFF switch to the OFF position, rotate the adjust 1 and adjust 2 knobs fully
counter-clockwise (to the minimum settings) and then you are ready to attach the battery
leads.
10) Insert the sensor or heater wires in the output terminals and secure by tightening
the screws. Connect +ve to Vout (V1 or V2) and -ve to the GND terminals adjacent to the
Vout.
11) Attach the red battery wire terminal to the AVRD Vin (+) with an in-line fuse (optional).
12) Attach the black battery wire terminal to AVRD GND (-), either one is ok.
13) Decide which sensor cables will be assigned to the V1, and which are to be assigned
to V2.
14) After these steps, you will have a neatly arranged set of heater wires attached to the
appropriate Vout1, and Vout2.
15) In the case of the AVRD is to be operated with power down option, connect a wire from
the SHDN to the control output designated for controlling the power down timing. In the
case of the AVRD not being used with the power down feature, do not connect any thing to
the SHDN terminal. Keeping SHDN open will disable the controlled power down feature,
keeping outputs enabled.
16) Check the wiring one more time with a continuity meter, making sure that Vout is not
connected to ground, and that all leads are connected properly.

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2.2 Power Sources
AVRD can be powered from any DC Power source supplying at least 10V and capable of
supplying a current of 5A maximum on each output (10A max. total). Operating voltage
range is 10V to 36VDC. The following are recommended DC power sources,
• Battery
• Solar Panel with backup battery
• AC outlet adapter with regulated DC output
• Regulated DC power
Some chargers will ground the output (-) lead, and have a common earth. In any case
be sure that the earth ground of the source is not used to ground the AVRD or in turn
the chassis. Only one ground can be allowed, and that is the earth ground next to the
logger. This is supposed to be attached with a green wire to indicate the earth connection,
di󰀨erentiated from the electrical neutral (or ground wires) that are black.
2.3 Operation
A typical system diagram shown below gives an example of a logger, battery, and power
from a solar panel, and how the regulators t into the overall system.
As shown in the example, one may control two di󰀨erent voltages from a single AVRD.
More adjustable voltages require additional AVRD regulator units. The adjustment knob on
each regulation output will vary the voltage up to 10Vdc or as low as 1.0 Vdc. The logger
connection to the 12V battery can be connected at the AVRD terminals, where the battery
connection is made. The wiring is simpler this way, and the connection is sturdy. One may
elect to have the logger independently supplied with power from an internal battery, or as
shown below.
Normally the rst time user will start with a choice of one AVRD regulator, anticipating that
two types of sensors may be selected, or two di󰀨erent voltages would be su󰀩cient. Refer
to the section on applications and sensor requirements for the di󰀨erent voltage settings on
your application.

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When the customer has 120 V AC or 220 V AC line power supplied nearby, the solar panel is
simply replaced by the battery charger and the battery size may be smaller than indicated. A
7 Ahr sealed lead acid battery has su󰀩cient capacity for most applications. Model numbers
BA5A, and BA7A are the Dynamax products for 5A-hr and 7 A-hr batteries, respectively. The
4A-hr battery is recommended for measurement systems having four sensors or less.
Setting / Changing Voltage
Once the logger, AVRD and all cables are connected, the operation and set-up is quite easy,
simply follow the steps below.
1. The rst time user should get a voltmeter and attach it to the Vin, and referencing
to ground. Make sure the voltage is greater than 10V if not charge the batteries
before proceeding.
2. If the voltage is greater than 10 VDC, turn the ON/OFF slide-switch to ON position.
Make sure Power LED is ON, if not check wiring to Vin terminal.
3. Attach voltmeter +ve to the Vout1 (V1), and referencing to ground. Then check
the sensor manual for the heater voltage. Turn on the AVRD adjustable knob
labeled Adj1. When you are ready, and turn the adjust knob clockwise to slowly
increase the voltage until the right setting is achieved. One turn is approximately
0.6 V increase (in clockwise direction) or increase (in counter clockwise direction).
4. Repeat the above step for setting the output voltage Vout2 (V2) from the AVRD.
5. Once the customer gets familiar with the logger operation, one may use the logger
to monitor the sensor supply, and make adjustments as needed. In this case the
logger acts as a voltmeter.
3.0 AVRD Applications
The purpose of the adjustable regulators from Dynamax is to have a stable, noise free
voltage excitation for sap ow sensors. Sap ow sensors o󰀨ered by Dynamax are constant
heat energy balance sensors, and the TDP sap velocity sensors are steady state heat
dissipation sensors. In both methods one major benet is the ease of supplying a constant
voltage to the heater elements. The devices that are responsible for providing a steady
regulated supply of voltage are the AVRD series of regulators.
In both methods of measuring sap ow di󰀨erential temperature readings within the sensors
are functions of the heat ux or the dissipation of heat. In general, an accurate heat
ux measurement depends on the steady application of power to the heater elements.
Otherwise, a uctuation in the power will cause an arbitrary temperature change, and
therefore a misrepresentation in heat ux as a change in sap ow.
New AVRD is a general-purpose adjustable voltage regulator for supplying excitation voltage to
a variety of sensors and DC powered systems. High current and high e󰀩ciency of this regulator
makes it extremely versatile for eld applications where power consumption is critical. The following
table shows application and number of AVRD’s congured with several Dynamax systems / kits.

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SYSTEMS WITH VOLTAGE REGULATION
Model Regulator Included Standard Maximum Upgraded System - Add:
Flow2 Internal 1A AVRD
Flow32-A AVRD AVRD
Flow32-B AVRD AVRD
Flow32-C AVRD AVRD
FLGS-TDP (2) AVRD -
FL32-GS8 AVRD AVRD
FL32-GS16 (2) AVRD -
FLDL-TDP - AVRD
DL2e - AVRD
DL3000 - AVRD
SV1 (Delta-T Devices Kit) - AVRD
The specic sensor excitation voltage requirements are found in the installation manual for
that sensor. To determine the voltage for specic conditions and the type of sensor refer
to the sensor installation manual. The following table gives a quick picture of the typical
voltage requirements.
SENSOR REQUIREMENTS
Model Type Range
SGA2-3 Dynagage Microsensors 2-3 V
SGA5 Dynagage Microsensor 3.5-4.5 V
SGA10-SGB25 Dynagage Stem Gauges 3.5-5 V
SGB35-SGA70 Dynagage Trunk Gauges 5-7 V
SGA100 Dynagage Trunk Gauges 6-10 V
TDP-10-50 Granier Sap Velocity Sensor 2-5 V
TDP-80 Dual Sap Velocity Sensor 7.5 V
TDP-100 Triple Sap Velocity Sensor 8 V
4.0 Safety and Maintenance
PRECAUTIONS
1. The AVRD series regulators are not waterproof. The AVRD’s should be installed in
protected enclosures, NEMA 2,3 or 4 rated.
2. The regulator is internally protected from over-current. Nevertheless, do not short output
(+) leads to ground or minus leads. This can cause damage to wires, the regulator and
eventually burn up the device.
3. In addition to over-current latching AVRD is protected by an external in-line fuse 15A; 5 x
20mm (considering 5A max current on each).

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4. Use wire with gage 16AWG or higher on the input to handle the higher current
requirements
5. +ve and –ve from the battery or any power source at the input must be wired with correct
polarity. +ve from battery connected to Vin and –ve from battery connected to the Gnd
terminal next to the Vin terminal.
MAINTENANCE
1. No regular maintenance is required. The regulators are sturdy devices, and give years of
trouble-free performance.
2. In case external fuse blows out due to over current or terminal short circuit replace the
fuse with same rating.
3. If the AVRD shuts down due to over current latch restart the AVRD by turning the slide-
switch OFF and ON.
5.0 Warranty
In an e󰀨ort to provide at most reliability of products in eld applications all Dynamax
products are tested for trouble free operation in the eld. AVRD along with all components
are warranted to be free from defects for one year after the purchase.

10808 Fallstone Rd #350
Houston, TX 77099, USA
Tel: [phone]
Fax: [phone]
www.dynamax.com