theleeco UEKA0300000A Disc Pump Drive PCB User Manual

theleeco UEKA0300000A Disc Pump Drive PCB

DISCLAIMER

This resource is provided “as is” and without any warranty of any kind, and its use is at your own risk. The Lee Company does not warrant the performance or results that you may obtain by using this resource. The Lee Company makes no warranties regarding this resource, express or implied, including as to non-infringement, merchantability, or fitness for any particular purpose. To the maximum extent permitted by law The Lee Company disclaims liability for any loss or damage resulting from the use of this resource, whether arising under contract, tort (including negligence), strict liability, or otherwise, and whether direct, consequential, indirect, or otherwise, even if The Lee Company has been advised of the possibility of such damages, or for any claim from any third party.

SPECIAL NOTICES

Throughout this User Manual, special notices relating to the safe and correct operation of the General Purpose Disc Pump Drive PCB are formatted and highlighted as follows:

CAUTION
Instructions to ensure correct operation of the equipment and/or for avoiding damage to the equipment.

WARNING
Instructions relating to the safety of the operator and avoiding injury.

INTRODUCTION

Piezoelectric Disc Pump
The Lee Company’s disc pumps are a multi-award winning technology which makes use of advances in the field of non-linear acoustics to offer the following unique features:

• silent operation
• ultra-smooth flow
• millisecond responsiveness
• compact form factor
• high-precision controllability

In contrast to conventional air pumping mechanisms (such as diaphragm and piston pumps), the disc pumps do not rely on the bulk compression of air within a cavity. Instead, the disc pump generates a high amplitude, high- frequency acoustic standing wave within a specially designed acoustic cavity. The operating frequency varies part-to-part and with pump operating conditions (e.g. temperature, pressure, etc). A dedicated drive circuit is therefore required to identify and track this frequency over time.

Figure 1 shows a simplified schematic: the out-of-plane motion of the actuator drives in-plane (radial) motion of the gas in the cavity and creates a standing pressure wave, resulting in the oscillating cavity pressure shown. The motion of the actuator is highly exaggerated: there is virtually no net volume change of the cavity during operation and at any given point in time there exists both a region of compression and a region of rarefaction within the cavity. Rectification of the alternating cavity pressure is the key to delivering useful pump performance and device lifetime. The Lee Company has addressed this need by developing a family of innovative valve designs based on lightweight polymer valve flaps. The disc pump technology is protected by a portfolio of both patent applications and granted patents.

The General Purpose Disc Pump Drive PCB

Following initial testing with the Piezoelectric Disc Pump Evaluation Kit, customers may elect to use the General Purpose Disc Pump Drive PCB [UEKA0300000A] in their own product design. This allows customers to forgo the time and effort required to design and integrate their own Disc Pump drive circuit and firmware. The General Purpose Drive PCB handles the specific pump drive requirements and provides a variety of easy-to-use interfaces, which enable simple integration with test systems, prototype devices, and final products.

For the most basic use case, a three-wire connection (supply voltage, ground and analog control) is all that is needed. For more sophisticated use cases, the Drive PCB can be controlled over a TTL-level serial UART link. The Drive PCB also implements closed-loop control (e.g. of pressure, vacuum or flow). Customers can provide analog sensor input (e.g. measured pressure or flow) to any of the PCB’s three analog inputs for this purpose. The Drive PCB can act as an I2C master, allowing communication with a selection of digital sensors, although it does not support I2C control by another master device. This manual provides information to aid the integration of the General Purpose Disc Pump Drive PCB with your system.

SAFETY

WARNING
The equipment described in this document is intended for use by skilled and competent personnel only. Further, the equipment is provided in a ‘bare’ format enabling users to integrate it into test fixtures, prototypes and product assemblies. The user should satisfy themselves that the equipment is, and remains fit for, the intended use. The user accepts that The Lee Company shall not be held responsible or liable for any injury, damage or loss to property, person or otherwise, resulting from use of the equipment. In order to aid assessment of the safety of the equipment, the following indicative electrical data are provided:

• A.C. voltage on the PCB: 120 Vpp max. (at 20 – 22 kHz)
• D.C. voltage on the PCB: 60 V max.

All disc pumps emit ultrasound in operation. The following data are provided for operation at maximum power (1.4W) at a distance of 30cm:

Sound pressure level: 70-80 dB SPL @ 30 cm typ. (at 20-22 kHz)1

1. Equivalent to <10 phon per ISO 226:2003 and related studies, 30 cm equivalent measurement distance

WARNING
Take care during use of the General Purpose Disc Pump Drive PCB not to create short circuits between exposed conductive parts of the PCBs. Short circuits may lead to malfunctioning and heating.

DRIVE PCB OVERVIEW

for connecting the disc pump.

2

|

Drive PCB Mating Connectors

| The board uses three connectors for communications, sensor inputs and power. The connectors are 1.27mm pitch, single-in-line headers. 2a, 2b and 2c are 10, 4, and 5-way headers respectively for a total of 19-pin header.

Table 1. General Purpose Disc Pump Drive PCB interface details

INSTALLATION

Mechanical – Drive PCB dimensions

The dimensions of the General Purpose Disc Pump Drive PCB are shown below.

Electrical – Pump “Flexi Tail” Connector
The disc pump uses an FFC (flat flex connector) compatible with most 8-way 0.5mm pitch FFC connectors. The General Purpose Disc Pump Drive PCB has such a connector, and it is important that the disc pump “Flexi Tail” is properly seated in this connector.

Electrical – Drive PCB Mating Connectors
The General Purpose Disc Pump Drive PCB uses three, 1.27mm pitch, single-in- line, pin headers to form the 19-pin header. Specifically, 4, 5, and 10-way headers. The 4 and 5-way headers are spaced by 1.5x the normal 1.27mm spacing so that the PCB can only be mounted in a mating 19-socket connector in the correct orientation. Matching 4, 5, and 10-way 1.27mm pitch, single-in-line sockets should be chosen to form a mating female connector for the General Purpose Disc Pump Drive PCB. Each socket should be able to accept a pin at least 3.2mm long.

Table 2. Drive PCB pin header mating connectors

Electrical – Drive PCB Pinout

Figure 7. Drive PCB Pinout

1. Note that the PCB does not support control by another I2C master device. The I2C function enables control of peripheral devices when connected to the Evaluation Kit Motherboard PCB.

SYSTEM OPERATION

Preparing the system for first use

• Remove the Drive PCB from protective the ESD bag
• Optional: Use The Lee Company Evaluation Kit to configure the Drive PCB
• Seat the Drive PCB into a matching connector
• Connect the pump

System control interfaces
The system provides multiple options for controlling the pump:

• Analog control
• Digital control over UART

Analog control
Pins 7 to 9 of the General Purpose Disc Pump Drive PCB have a 0 to 3.3 V analog input. A single analog input can be configured to control pump drive power (“open-loop” control). Or multiple analog inputs can be used together, for instance, one to measure the output from a pressure sensor, and another to receive a target pressure. The Drive PCB can then be configured to perform closed loop control between the two analog inputs. GPIO A and B can be used to toggle the pump ON/OFF. The Drive PCB applies an internal pull-up so these pins can be left floating. Changing the state of either pin toggles the pumps ON/OFF state.

Disc Pump Control App
The Disc Pump Control App can be used to configure and control the Drive PCB while mounted to a Lee Company Evaluation Kit Motherboard PCB – for example, to set the control mode and associated parameters. If desired, configuration settings can be saved to the Drive PCB for use on power-up, enabling the Disc Pump Control App to be used as a production configuration tool prior to installing the Drive PCB in the final system. Refer to the ‘Piezoelectric Disc Pump Evaluation Kit User Manual’ for further information on using the Drive PCB, Motherboard and Pump Control App together. This functionality can be configured using the UART interface, refer to The Lee Company Technical Guide ‘Communications Technical Guide: Piezoelectric Disc Pumps’ for more information.

Digital control
The digital UART interface can be used to control the PCB, without any reliance on the analog inputs. Refer to The Lee Company Technical Guide ‘TG003: PCB Serial Communications Guide’ for more information.

ACCESSORIES

The following accessories are available for the General Purpose Disc Pump Drive PCB.

UACX0500100E (Breakout PCB)
The Breakout PCB allows the General Purpose Disc Pump Drive PCB to be connected easily to two 0.1” (2.54 mm) single inline headers, suitable for integration with 0.1” prototype board, enabling rapid prototyping and testing at the start of the development process.

Materials: Printed circuit board FCB

SUPPORT

The Lee Company website (www.theleeco.com/discpumps) provides technical information, FAQs, troubleshooting and documentation for download. For additional technical support, please contact your Lee Sales Engineer.

CERTIFICATE OF CONFORMITY

REVISION HISTORY

certificate of conformity.
220513| 13 May 2022| Initial release.

• THE LEE COMPANY
• Tel: 860-399-6281
• www.theleeco.com

References

• The Lee Company | Miniature Precision Fluid Control

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