Fall 2012 Human Powered Gym: Pedal Powered Charging Station
Kyle Zampaglione, Darshan Kasar, Matt Roeschke Berkeley Engineering and Sustainability Technology Labs Advisors: Prof Alice Agogino, Prof George Anwar
Zampaglione
Pedal Powered Charging Station
Abstract
12/15/2012
The advantage of the Orion is that it does not need a battery to turn on its circuitry. The Orion will power on from the input voltage. For the bike, this means that pedaling will directly turn on the DC/DC converter and variably light the LEDs with whatever voltage is being put through. The lights will vary in brightness until the system reaches 12V; the output voltage of the Orion. After sufficient testing of the bike, it was concluded that the maximum producible voltage was 32V, just short of the 35V maximum of the Orion. A property specific to this model of Orion is no undervoltage shutdown. This means that from 0-14V, the converter will act as an open circuit and let the electricity flow through instead of store it until the voltage reaches an appropriate range. The educational purpose of the LEDs is simply a visual representation. The charging aspect of the bike is the functional side of this prototype. While few changes were made to the charging system since the summer, the modifications made were important to the overall system. A switch was added to allow the user to turn the charging system on and off. With the switch off, the user can simply observe the LEDs variable brightness. When the switch is turned on, the battery connection to the Xantrex is completed. The user can now charge his or her phone from the Apple charging attachment. While the user charges his or her phone, the LEDs still maintain their variable brightness. The switch is important because it prevents the Xantrex from pulling charge from the battery while the bike is not in use. To finish the bike aesthetically, the casing was modified. The right side of the case had to be cut away to allow the motor to protrude. Holes were drilled in the sides of the plastic casing to allow for axles to protrude. Clear polycarbonate was purchased to cover the rest of the electrical components below the reach of the case. The clear polycarbonate allows onlookers to see the componentry and LEDs. The motor was also given a clear polycarbonate case. After these modifications, the case bolted back together using its original mounts.
The pedal powered charging station is a continuation of work done over the summer of 2012. While the result from summer was flawlessly functioning, many aspects were lacking aesthetically. The Fall 2012 semester’s goal was to turn the pedal powered charging station into a finished product, ready for education in the Recreational Sports Facility. After several attempts at improving the current system, a finalized version was created for implementation in the RSF. The finished system charges older generation Apple products and lights LEDs to display varying power input. Final Product The final product builds on the design from the summer of 2012. The charging system has had little modification done to it. All wires have been replaced and cleaned up in appearance and quality of connections. A major addition to the bike is the LED display system. The LED display system consists of rows of LEDs along the bottom edges of the drive unit and up the length of the handlebar pillar. The LEDs serve as visual feedback to the user of how much power he or she is generating. As the user pedals faster, the LEDs brighten. This simple system shows to the user real-time results of their working out and bathes the exercise machine in a bright blue aurora. The LED lighting system operates on a similar system to the charging system. The major difference between these systems is the lack of battery in the LED system. The Xantrex C-35 in the charging system requires a battery to start the DC/DC conversion process. The LED system uses a much smaller Orion 24/12-5 DC/DC converter. See Appendix 1 for spec sheet on these components.
Electrical Notes **Important**: due to lack of wires, black is positive and brown is negative. This convention is consistent for most connections. Figure 1: Orion 24/12-5 Source: http://www.neosolar.sk
2
Zampaglione Pedal Powered Charging Station 12/15/2012 of power required for larger loads while maintaining the **Important**: The color of the wires coming directly same pedaling cadence. As more load was added to the from the motor (black and red) should be ignored. Due system, it was found that exactly the opposite to the reversal of polarity from running the motor as a happened; the bike became easier to pedal. Though the generator, the wires are reversed. This was confused system did require more power to satisfy the load, the several times in the construction process with the input was becoming easier to spin. placement of the diode. It is best to ignore the color of This phenomenon is caused by the inductance these wires and start with the color convention of black of the motor creating power in the opposite direction. as positive and brown as negative. The braking power can be modeled by P= I2R where I is **Important**: Since the Xantrex was wired previously, the current returned to the motor and R is the internal the wires coming directly from it were left the same. resistance of the motor. From this model it is easy to The white wires are positive and the black are negative see that when shorting the motor, the maximum on the output of the Xantrex. At the parallel junction at amount of current can flow back into the windings, the end of each of these wires, the coloring goes back creating a huge stopping force, or in the bike’s case, to the correct black and brown. The only black negative resistance to the user. wire in this system runs from the Xantrex to the parallel The implemented system demonstrated this junction of the battery and charger, and from that braking power, just not in the intended way. As more parallel junction to the charger. Likewise, the only white load was added to the system, less current would flow positive wires run from the Xantrex to the parallel back to the motor, thus creating less braking power. An junction of the charger and battery, and from the easy way to think about this is that as more load is parallel junction to the charger. added to the system, the leads of the motor move towards an open circuit. An open circuit is easy to For a schematic of this system see Appendix 2. visualize because when nothing is attached to a DC motor, it spins relatively freely. Through experimentation it was found that even small amounts of resistance would cause the Physical Feedback Problems motor to still feel like an open circuit. A potential reason for this was actually having too nice a motor. DC motors The team made several attempts at creating a are designed to have small, almost negligible internal physical feedback system. This physical feedback system resistances. Referring back to the braking power aimed to increase resistance to the user as he or she formula, a current that is nearly infinite is needed to attempted to power larger devices. For example, to oppose a resistance that is nearly zero. Any load will power 4 60watts, the user would have to output cause this current to rapidly drop from infinity. For this 240watts. This would require a reasonable amount of reason, it was extremely difficult to feel considerable effort from the user. Unfortunately it was found that resistance at the user input with any load across the creating a high resistance and a high power output motor. power system was nearly impossible to do After many tries it was deemed unfruitful to simultaneously. The reason for this is due to the continue to develop a system that could create both properties of the back EMF that generates the voltage high power output and high resistance and be in this system. integrated into the current work. Outside parties who When a DC electric motor is driven by an have made similar bikes that did give accurate feedback external force, it creates a back voltage (back EMF). This were contacted and it was found that they used voltage is caused by induction and varies with speed. simulated feedback systems for education purposes. This is what makes DC motors viable generators for systems that can turn them near their operating speed. The bike can easily turn the motor at the required Future Considerations 2400rpm necessary to create 24V. Normally with electronic devices, the power One very important future consideration would drawn increases with the amount of load. For the bike be to use an actual generator for the system. Currently system, the goal was to increase feedback to the user as the system uses a DC motor. The difference between DC load increased. This would represent the larger amount motors and generators is the number of windings. 3
Zampaglione Pedal Powered Charging Station 12/15/2012 users about energy usage through visual and physical Generators have far more windings which allows them means. to generate more power on each turn. This would hopefully mean that the generator has a greater internal resistance, which would create more resistance for the user. Acknowledgements A common generator that could be tested for this project is a car alternator. A car alternator is an AC The Pedal Powered Charging Station would like generator with built in inverter that outputs 12V DC. Car to thank the staff in the ME machine shop in alternators range from 45-120A of output current; Etcherverry and Hesse for their continued help with meaning they produce well over 1000watts of power fabricating parts. The team would also like to thank Tom when connected to an appropriate load. A car Clark for his electrical input and giving us access to alternator was purchased for the project but it has not wires and other electrical necessities. Finally the team been tested due to complications with starting. would like to thank Professor Agogino and Professor Alternators require a nominal starting current to create Anwar for their continued support and interest in this the initial inductance in the coils. After the alternator project. has started turning, the input current can be shut off. No system has been made yet to create this current. Fixtures will also be needed to implement the alternator in the current system. Another future consideration is to switch the Apple charger for a standard 12V to USB charger. These have also been purchased for the project but have not been rewired for the system. This is a simple change and will mean that any user with a USB charge capable device can use the bike for power. One last future consideration is to switch the belt configuration for chains. The system was originally changed to belts because of concern that the motor could not be spun fast enough to generate the required voltage. Belts allowed much higher ratios between pulleys. Now that the entire system only requires between 12-20V powering both the Xantrex and Orion, it would be safe to switch back to the lower ratios of chains. Some advantages of chains drive are that the lengths of chains are adjustable and they can be run slightly out of line. The belt system is a hassle because each pulley must be perfectly aligned or else the belt will slip off. Conclusion Overall, this semester saw positive progress on the bike. Though much of the time was spent trying to develop a feedback system for the user that ultimately failed, the knowledge gained will be useful for future developers. The bike is fully functioning and ready for use in an educational setting. The changes detailed in the previous section would simply improve on the design. The project has ultimately achieved what it set out to do: charge simple electronic devices and educate 4
Appendix 1 C Series Controllers Charge, Diversion, or Load Controllers
C40 & C60
C35
CM
A charge controller is an important system component that regulates the voltage generated from your renewable energy system and properly maintains your batteries. It protects your batteries from being over and under charged, and ensures maximum battery life. Considered to be the best in the industry, Xantrex Charge Controllers offer a variety of features. The C Series offers three models, the C35, C40, and C60, designed for 35, 40, and 60 amps of DC current.
Features Silent, pulse width modulated (PWM), high efficiency operation. Three-stage battery charging (bulk, absorption, and float) with optional temperature compensation. Automatic overload protection in both active and passive modes. PV array short circuit and reverse polarity protection. Durable construction. Microprocessor controlled.
Xantrex Technology Inc. Headquarters 8999 Nelson Way Burnaby, British Columbia Canada V5A 4B5 800 670 0707 Toll Free 604 420 1591 Fax 5916 195th Street NE Arlington, Washington USA 98223 360 435 8826 Telephone 360 435 2229 Fax
As a Solar Charge Controller When used as a solar charge controller, the C40 can control 12, 24, or 48 VDC array operation and the C35 and C60 can control 12 and 24 VDC array operation. All units offer selectable settings for NiCad, flooded lead acid, gel, or absorbed glass mat batteries.
As a DC Load Controller As a DC load controller, the C Series has a low voltage disconnect warning indicator and field adjustable set points that govern automatic low and high voltage disconnect. Manual reset switch for emergency low voltage operation.
As a Diversion Controller The C Series automatically directs extra power to a dedicated load, such as an electric water heater, and ensures batteries are never over-charged.
Options Plug-in remote temperature sensor (BTS) for increased charging precision. Cumulative amp-hour meter (CM) that can be installed on the face of the controller, or remotely (CM/R), up to 100 feet (30 m) away.
Š 2003 Xantrex Technology Inc. All rights reserved. Xantrex is a trademark of Xantrex International. P/N 970-0026-01-03 Rev C Printed in Canada
www.xantrex.com
C Series Controllers Charge, Diversion, or Load Controllers
Electrical Specifications Model
C35
C40
C60
Voltage Configurations
12 and 24 VDC
12, 24, and 48 VDC
12 and 24 VDC
Max. PV Open Circuit Array Voltage
55 VDC
125 VDC
55 VDC
Charging / Load Current (@ 25 °C)
35 amps DC
40 amps DC
60 amps DC
Max. Peak Current
85 amps
85 amps
85 amps
Max. Voltage Drop Through Controller
0.30 volts
0.30 volts
0.30 volts
Typical Operating Consumption
15 ma
15 ma
15 ma
Typical Idle Consumption
3 ma
3 ma
3 ma
Recommended Breaker Size
45 amps
50 amps
60 amps rated at 100% continuous duty
Recommended Wire Size
#8 AWG
#8 AWG
#6 AWG rated at 90 °C
Lead Acid Battery Settings
Adjustable
Adjustable
Adjustable
NiCad Battery Settings
Adjustable
Adjustable
Adjustable
Load Control Mode
Low Voltage Reconnect - Adjustable (sticker provided with unit) all models Low Voltage Disconnect - User selectable manual or automatic reconnection - includes warning flash before disconnect and provides a one time, user selected grace period) all models
General Specifications Specified Temperature Range
32 °F to 104 °F (0 °C to 40 °C)
Enclosure Type
Indoor, ventilated, powder coated steel with 3/4” and 1” knockouts
Unit Weight
2.5 lb (1.2 kg)
3.0 lb (1.4 kg)
3.0 lb (1.4 kg)
Shipping
3.0 lb (1.4 kg)
3.5 lb (1.6 kg)
3.5 lb (1.6 kg)
Dimensions (H x W x D)
8.0” x 5.0” x 2.5”
10” x 5” x 2.5”
10” x 5” x 2.5”
20.3 cm x 12.7 cm x 6.4 cm
25.4 cm x 12.7 cm x 6.35 cm
(25.4 cm x 12.7 cm x 6.35 cm)
12.4” x 7“ x 2.5”
12.4” x 7“ x 2.5”
12.4” x 7“ x 2.5”
31.5 cm x 17.8 cm x 6.4 cm
31.5 cm x 17.8 cm x 6.4 cm
31.5 cm x 17.8 cm x 6.4 cm
Shipping Dimensions (H x W x D) Mounting
Vertical wall mount - indoor only
Altitude - Operating
15,000’ (4,572 m)
Altitude - Non-Operating
50,000’ (15,240 m)
Warranty
2 years
Part numbers
C35, C40, C60 - Controllers CM - Front Display Panel CM/R-50, CM/R-100 - Remote Display Panel BTS - Battery temperature sensor
Features & Options Regulation Method
Solid state, three-stage (bulk, absorption, and float), pulse width modulation
Field Adjustable Control Setpoints
Two user adjustable voltage setpoints for control of loads or charging sources - settings retained if battery is disconnected
Display Panel
CM, CM/R-50, or CM/R-100 - optional LCD - backlit, alphanumeric display showing battery voltage, DC amperage, cumulative amp hours, and amp hours since last reset - remote includes 50’ (15 m) or 100’ (30.5 m) cable
Equalization Charge
User selectable manual or automatic equalization - every 30 days
Battery Temperature Sensor
BTS - optional remote battery temperature sensor for increased charging precision
Regulatory Approvals UL Listed to UL 1741 - 1999 and to CSA 22.2 No. 107.1-95 Standards, CE compliant
Specifications subject to change without notice.
Orion DC/DC Converters www.victronenergy.com
Remote on-off connector on the high power models (see table below) The remote on-off eliminates the need for a high current switch in the input wiring. The remote on-off can be operated with a low power switch or by the engine run/stop switch (see manual).
All models with adjustable output can also be used as a battery charger For example to charge a 12 Volt starter or accessory battery in an otherwise 24 V system. All models with adjustable output can be paralleled to increase output current Up to five units can be connected in parallel.
Orion 24/12-5
The Orion 12/27,6-12: a 24 V battery charger (see page 2) To charge a 24 V battery from a 12 V system. The output voltage of this model can be adjusted with a potentiometer A super wide input range buck-boost regulator: the Orion 7-35/12-3 (see page 2) The Orion 7-35/12-3 is an isolated converter with a very wide input range, suitable for both 12 V and 24 V systems, and a fixed 12,6 V output. Easy to install Delivery includes four Insulated Fastons Female Crimp 6.3 mm (eight Fastons in case of the Orion 24/12-40).
Orion 24/12-17
Orion 24/12-25
Orion 24/12-40
Orion 24/12-70
NEW Non isolated converters
Orion 24/12-5
Orion 24/12-12
Orion 24/12-17
Orion 24/12-25
Orion 24/12-40
Orion 24/12-70
Orion 12/24-8
Orion 12/24-10
Orion 12/24-20
18-35
18-35
18-35
18-35
18-35
18-35
9-18
9-18
9-18
Undervoltage shutdown (V)
-
14
14
14
14
14
8
8
8
Undervoltage restart (V)
-
18
18
18
18
18
10
10
10
no
no
no
yes
no
yes
no
yes
yes
12
Adjustable 10–15V
12
Adjustable 10–15V
24
Adjustable 20-30V
Adjustable 20-30V
Input voltage range (V)
Output voltage adjustable with potentiometer Output voltage (V)
12
12
F set 13,2V
F set 13,2V
F set 26,4V
F set 26,4V
Efficiency (%)
92
95
94
96
95
92
95
95
93
Suitable to buffer-charge a battery
no
no
no
yes
no
yes
no
yes
yes
Can be connected in parallel
no
no
no
yes
no
yes
no
yes
yes
Continuous output current (A)
5
12
17
25
40
70
8
10
20
Max. Output current (A)
5
20
25
35
55
85
20
20
30
Fan assisted cooling (temp. controlled)
no
no
no
no
yes
yes
no
no
yes
Galvanic isolation
no
no
no
no
no
no
no
no
no
Off load current
< 5mA
< 7mA
< 7mA
< 15mA
< 20mA
< 20mA
< 10mA
< 15mA
< 30mA
Remote on-off
no
no
no
yes
yes
yes
no
no
yes
-20 to +55°C
-20 to +55°C
-20 to +55°C
-20 to +55°C
-20 to +55°C
-20 to +55°C
-20 to +55°C
-20 to +55°C
-20 to +55°C
M6 bolts
Faston tabs 6.3 mm
Faston tabs 6.3 mm
M6 bolts
Operating temperature range (derate 3% per °C above 40°C) DC connection Weight kg (lbs) Dimensions hxwxd in mm (hxwxd in inches)
Notes: -
Faston tabs 6.3 mm
Faston tabs 6.3 mm
Faston tabs 6.3 mm
Faston tabs 6.3 mm
Double Faston tabs 6.3 mm
0,2 (0.40)
0,3 (0.65)
0,3 (0.65)
0,7 (1.55)
0,85 (1.9)
0,9 (2.0)
0,4 (0.8)
0,4 (0.9)
0,9 (2.0)
45x90x65 (1.8x3.5x2.6)
45x90x100 (1.8x3.5x3.9)
45x90x110 (1.8x3.5x3.9)
65x88x160 (2.6x3.5x6.3)
65x88x185 (2.6x3.5x7.3)
65x88x195 (2.6x3.5x7.7)
45x90x115 (1.8x3.5x4.5)
45x90x125 (1.8x3.5x4,5)
65x88x195 (2.6x3.5x7.7)
Other in- or output voltages at request All natural convection cooled models can also be modified to IP65
Victron Energy B.V. | De Paal 35 | 1351 JG Almere | The Netherlands General phone: +31 (0)36 535 97 00 | Fax: +31 (0)36 535 97 40 E-mail: sales@victronenergy.com | www.victronenergy.com
Isolated converters
Orion xx/yy-100W
Orion xx/yy-200W
Orion xx/yy-360W
Power rating (W)
100 (12,5V/8A or 24V/4A)
200 (12,5V/16A or 24V/8A)
360 (12,5V/30A or 24V/15A)
Galvanic isolation
yes
yes
yes
25
30
30
no
yes
yes
Temperature increase after 30 minutes at full load (°C) Fan assisted cooling (temp. controlled) Weight kg (lbs) Dimensions hxwxd in mm (hxwxd in inches)
0,5 (1.1)
0,6 (1.3)
1,4 (3.1)
49 x 88 x 152 (1.9 x 3.5 x 6.0)
49 x 88 x 182 (1.9 x 3.5 x 7.2)
64 x 163 x 160 (2.5 x 6.4 x 6.3)
Input voltage (xx): 12 V (9 – 18 V) or 24 V (20 – 35 V) or 48 V (30 – 60 V) or 96 V (60 – 120 V) or 110V (60 – 140V) Output voltage (yy): 12,5 V, 24 V or 48V
Isolated 24V battery charger: Orion 12/27,6-12 Input 9 – 18 V, output 27,6 V, current limit 12 A, fan assisted cooling Output voltage adjustable with potentiometer Weight 1,4 kg (3.1 lbs), dimensions 64 x 163 x 160 mm (2.5 x 6.4 x 6.3 inch) Isolated buck-boost regulator: Orion 7-35/12-3 Input 7 – 35 V, output 12,6 V current limit 3 A, derate current linearly from 3 A at 18 V to 1,5 A at 7 V Weight 1,4 kg (3.1 lbs), dimensions 64 x 163 x 160 mm (2.5 x 6.4 x 6.3 inch) Common Characteristics Output voltage stability
2 % (Orion 12/24-7 and Orion 12/24-10: + 0% / - 5%)
Output voltage tolerance
3%
Output noise
< 50 mV rms
Off load current
< 25 mA (isolated converters)
Efficiency
Non isolated: appr. 92% Isolated: appr. 85%
Isolation
> 400 Vrms between input, output and case (isolated products only)
Operating temperature
- 20 to + 30°C (0 to 90°F). Derate linearly to 0 A at 70°C (160°F)
Humidity
Max 95% non condensing
Casework
Anodised aluminum
Connections
6.3 mm (2.5 inch) push-on flat blade connectors
Protection: Overcurrent Overheating Reverse polarity conn. Overvoltage Standards: Emission Immunity Automotive Directive
Short circuit proof Reduction of output voltage Fuse and reverse connected diode across input Varistor (also protects against load dump) EN 50081-1 EN 50082-1 95/45/EC
Orion isolated 100W
Victron Energy B.V. | De Paal 35 | 1351 JG Almere | The Netherlands General phone: +31 (0)36 535 97 00 | Fax: +31 (0)36 535 97 40 E-mail: sales@victronenergy.com | www.victronenergy.com
Orion isolated 360W
1N3211 LED Strips + In+
Out+ Orion 24/12-5
Motor
Appendix 2
In-
Out-
In+
LED Strips In-
Out+ Xantrex C35 Out-
Switch PowerSonic Battery 12 V
Input + Charger Input -
Output
To Ipod Charger