Digitimer DS4 User manual

Digitimer DS4

Bi-phasic Stimulus Isolator

OPERATOR'S MANUAL

“Digitimer” is a registered trade mark of Digitimer Limited

DS4 Bi-phasic Stimulus Isolator DS4 Operator's Manual Issue 1.1

Product Registration

Please take time out to register your new product.

Details are included in the Introduction.

You can even do it online at:-

www.digitimer.com/register

DS4 Bi-phasic Stimulus Isolator DS4 Operator's Manual Issue 1.1

Table of Contents

Introduction ............................................................................................................. 5

Precautions and Warnings ..................................................................................... 6

Operator’s Manual ............................................................................................ 6

Explosion and Fire ............................................................................................ 6

Damage ........................................................................................................... 6

Moisture .......................................................................................................... 6

Electrical Interference ....................................................................................... 6

Contact Address ................................................................................................... 6

Servicing & Maintenance ....................................................................................... 6

Environmental Considerations ............................................................................... 6

Product Registration ............................................................................................. 7

Why Register your purchase? ............................................................................ 7

How to Register your purchase .......................................................................... 7

Product announcement mailing list .................................................................... 7

Unpacking ............................................................................................................ 7

Included Items ..................................................................................................... 7

Optional Accessories ............................................................................................. 7

Declaration of Conformity ..................................................................................... 8

Functions & Features ................................................................................................ 9

Overview of the Controls/Connections ................................................................... 9

Power Connection ............................................................................................ 9

Power Zone ...................................................................................................... 9

Gate Zone ...................................................................................................... 10

Input Zone ..................................................................................................... 10

Output Zone................................................................................................... 10

Output Characteristics ........................................................................................ 11

Checking Actual Output Current ...................................................................... 12

Output Capacitance and Risetime .................................................................... 12

How Constant is the Constant Current Output?................................................. 12

DS4 Bi-phasic Stimulus Isolator DS4 Operator's Manual Issue 1.1

Frequency Response ....................................................................................... 12

Inactivity Sensor ................................................................................................ 13

Internal Jumper Selection ................................................................................... 14

Battery Life ........................................................................................................ 15

Battery Testing ................................................................................................... 16

Battery Replacement .......................................................................................... 16

Rack Mounting ................................................................................................... 16

References ............................................................................................................. 17

DS4 Specifications .................................................................................................. 18

Warranty ............................................................................................................... 19

Obtaining Warranty Service ................................................................................. 19

Product change or discontinuation ....................................................................... 19

Operator Notes ...................................................................................................... 20

Index of Figures & Tables

Figure 1 The DS4 Bi-phasic Stiimulus Isolator. ............................................................. 5

Figure 2 Positioning of the DC power supply socket on the DS4. ................................... 9

Figure 3 The POWER zone of the DS4 front panel. ....................................................... 9

Figure 4 The GATE zone of the DS4 front panel. ......................................................... 10

Figure 5 The INPUT zone of the DS4 front panel. ....................................................... 10

Figure 6 The OUTPUT zone of the DS4 front panel. ................................................... 11

Figure 7 Graph of deliverable current (hatched area) depending upon load. ............... 11

Figure 8 Method to monitor current actually delivered. ............................................... 12

Figure 9 Frequency Response Characteristics. ........................................................... 13

Figure 10 Effect of the inactivity sensor on stimulus initiation. .................................... 14

Figure 11 Location of the internal jumpers. ............................................................... 14

Table 1 Expected “Control” battery life. .................................................................... 15

Table 2 Expected “Stimulus” battery life. ................................................................... 15

Figure 12 DS4 battery compartment labelling. ........................................................... 16

DS4 Bi-phasic Stimulus Isolator DS4 Operator's Manual Issue 1.1

Introduction

The DS4 has been developed to meet the needs of laboratory scientists who require a stimulus isolator that

can output a bi-phasic isolated constant current stimulus in response to an external analogue command voltage

signal, provided by a computer DAC via software or a signal generator. Such a requirement is already met by

our NeuroLog System in the form of the NL512 Biphasic Buffer and NL800A Stimulus Isolators, but the DS4

provides our first standalone device to meet this need.

The DS4 accepts a variety of voltage input ranges (±1V, ±2.5V, ±5V and ±10V) and produces a constant

current stimulus output in 4 overlapping ranges (±10µA, ±100µA, ±1mA and ±10mA) from a compliance

voltage of approximately ±44V. In addition, the DS4 has a GATE input which allows multiple DS4's to be

connected to a single analogue voltage source, with each DS4 being digitally enabled, separately.

One of the problems with stimulators that make use of an external voltage source to define a stimulus

waveform is that small offsets or noisy baseline signals from the DAC's used to drive them can result in

unwanted battery drain or perhaps worse, low amplitude stimulation. The DS4 uses a special "inactivity

sensor" to monitor the input voltage and disable the DS4 output if this voltage falls below 0.15% of the full

scale value (in -ve or +ve directions) for a user selectable time period of 100ms, 200ms, 1s or 2s. Unlike

other devices which only produce an output when the input voltage exceeds a threshold value, this "inactivity

sensor" reduces battery usage and damaging "leak currents" during infrequent stimulation, while at the same

time maintaining low levels of zero crossing distortion for repetitive waveforms.

The DS4 uses an external power supply to power the input control circuitry and readily available/inexpensive

batteries to provide the opto-isolated stimulus voltage source. Batteries are only used when a stimulus is

commanded by an input voltage waveform.

Figure 1 The DS4 Bi-phasic Stiimulus Isolator.

DS4 Bi-phasic Stimulus Isolator DS4 Operator's Manual Issue 1.1

Precautions and Warnings

Operator’s Manual

Carefully study this Operators Manual before using the DS4 Bi-phasic Stimulus Isolator.

Explosion and Fire

The DS4 must not be used in an explosive atmosphere or volatile atmosphere.

Damage

The DS4 and/or any accessories must not be used if there are any signs of external damage.

Moisture

The DS4 and/or any accessories must not be used if any parts are wet or damp.

Electrical Interference

This unit has been fully tested for European (CE) EMC conformity. This unit should NOT be used near radio

transmitters. If any ‘strange’ behaviour of the unit is noted, discontinue use immediately and refer to a qualified

EMC engineer.

Contact Address

Digitimer Limited

37 Hydeway

Welwyn Garden City

AL7 3BE

Telephone:- (UK) 01707 328347 (Int.) +44 1707 328347

Fax:- (UK) 01707 373153 (Int.) +44 1707 373153

E-mail:- sales@digitimer.com or technical@digitimer.com

Website:- www.digitimer.com

Servicing & Maintenance

This equipment does not require any regular maintenance but if you would like your DS4 to be serviced we

are happy to do so. Please contact us for a reference number and instructions before despatching the unit.

Before each use - The case and all interconnecting cables should be inspected for any damage. The equipment

(or the lead) should be sent for repair if any damage is found.

Environmental Considerations

The European Union has adopted Directive 2002/96/EC on Waste Electrical and Electronic Equipment (WEEE),

with requirements that went into effect August 13, 2005. WEEE is intended to reduce the disposal of waste

from electrical and electronic equipment by establishing guidelines for prevention, reuse, recycling and

recovery.

As part of our legal obligation, Digitimer Limited is a registered EEE producer. Our WEEE registration number

is WEE/BJ0052TQ. For further information relating to the correct method of disposal of any of our equipment,

which features this label , please contact us.

DS4 Bi-phasic Stimulus Isolator DS4 Operator's Manual Issue 1.1

Product Registration

For a speedy response to all your questions now and in the future, please take time out to register your new

DS4 at www.digitimer.com/register now! Product registration permits us to quickly advise you of any safety

matters or new product information. This web address is your point of contact for all questions regarding the

DS4. The site’s contents are now growing rapidly, so please bookmark it so that you visit it regularly to check

out the new items.

Why Register your purchase?

 Digitimer Limited periodically offers enhancements and updates to our products. Without product

registration, users of our products may miss out on announcements of important enhancements to

the products that they are using

 Digitimer Limited does not make our customer list available to anyone else. Any information that you

provide to us is strictly confidential.

How to Register your purchase

Product registration can be accomplished in two ways. You may fill out and mail in the product

registration/warranty card supplied with each Digitimer Limited product. You may also register on-line at our

www.digitimer.com/register website.

Product announcement mailing list

Digitimer Limited has e-mailing lists which we use as our primary outlet for announcements of new products,

product enhancements and product updates. We strongly recommend that all users of our products sign up

for the list that is most appropriate to their area of interest. E-mail is kept to a minimum and list membership

is kept in the strictest confidence. Only Digitimer Limited can send mail to members of our e-mailing lists.

You may join the DS4 mailing list through our www.digitimer.com/register website.

Unpacking

After unpacking the DS4 Bi-phasic Stimulus Isolator from the shipping carton, please inspect it for any sign of

shipping damage. Please contact the carrier and your Distributor, or Digitimer Limited, immediately if there is

any damage. Do not dispose of the shipping carton. The carrier will want to examine the shipping carton to

process a damage claim. Digitimer Limited and their Distributors insure all shipments to cover shipping

damage.

It is also advisable to keep the shipping carton in the event that the instrument needs to returned for service.

Included Items

 DS4 Bi-phasic Stimulator

 ±15V DC Power Supply (input requirements 110-220VAC)

 Mains lead

 Pair of output plugs (NL985P)

 Operator's Manual (this document)

Optional Accessories

Digitimer can supply extra sets of output plugs (NL985P) for user connection to stimulating electrodes, as well

as 1.5m BNC cables (D185-TC3). We also stock sets of the ten batteries (DS4-BATT) which provide the

output power source for the stimulator. One or two stimulators may be mounted in a 19" rack using a specially

fabricated frame (model D121-11).

DS4 Bi-phasic Stimulus Isolator DS4 Operator's Manual Issue 1.1

Declaration of Conformity

DS4 Bi-phasic Stimulus Isolator DS4 Operator's Manual Issue 1.1

Functions & Features

Overview of the Controls/Connections

Power Connection

The DS4 control circuitry is powered by the supplied ±15V DC power supply adaptor which must be connected

to the DS4 via the socket illustrated in Figure 2. The supplied mains lead should then be used to connect the

DC power supply adaptor to a suitable mains supply (110-220V AC). Once all connections have been made,

the mains socket and the DS4 can be switched on.

Figure 2 Positioning of the DC power supply socket on the DS4.

Note that the DS4 is NOT a re-chargeable unit and the DC power supply must remain connected

and switched on while the DS4 is in use.

Power Zone

The DS4 has a POWER switch in the middle of the front panel which switches the unit on or off (by

disconnecting the DC power supply). When the power is switched on (toggle switch up), the green LED is lit.

It is recommended that the DS4 is switched off when not in use, as significant battery drain will occur if a

voltage continues to be applied at the INPUT, when the DS4 is switched on.

Figure 3 The POWER zone of the DS4 front panel.

DC Power Supply

Input Socket

DS4 Bi-phasic Stimulus Isolator DS4 Operator's Manual Issue 1.1

Gate Zone

A BNC socket is provided to allow a TTL command to “Gate” the output on or off. This feature means that a

command voltage signal can be applied continuously at the INPUT and the stimulus turned on and off via

digital control at the GATE input. Further, a single command voltage can be applied to multiple DS4 units with

individual digital lines used to turn specific DS4 outputs on or off.

A toggle switch is provided which enables (UP) or disables (DOWN, labelled OFF) the stimulus output. The

amber LED is lit when both the GATE is switched on (toggle switch up) and a TTL high input is being applied

at the GATE input (or this input is open circuit), indicating that the output is enabled. The maximum voltage

that can be applied at the GATE input is ±15V.

IMPORTANT NOTE: Even if the GATE input is disconnected, the GATE toggle switch must be in the UP

position for the DS4 to deliver a stimulus.

Figure 4 The GATE zone of the DS4 front panel.

Input Zone

A command voltage waveform is applied at this BNC socket and is used by the DS4 to determine the shape of

the stimulus it delivers. The DS4 accepts various input voltage ranges, but is factory set to ±10V. An internal

jumper allows the operator to change the input voltage range to ±1V, ±2.5V or ±5V to match the output

range available from the signal generator being used. Please refer to Internal Jumper Selection for further

details. If the input voltage range is changed, this should be indicated by placing a marking in the appropriate

box on the front panel. The maximum voltage that can be applied at this input is ±12V.

The INPUT zone of the DS4 front panel includes a pair of amber LEDs which illuminate when the input voltage

exceeds +0.15% or -0.15% of the full scale voltage.

Figure 5 The INPUT zone of the DS4 front panel.

Output Zone

The OUTPUT zone of the DS4 front panel includes a pair of 2mm touch proof sockets and a range selector

switch which allows the operator to adjust the output current range from ±10µA to ±10mA, from the

compliance voltage source of ±44V. If the DS4 is set to an input voltage range of ±10V and the output range

dial is set to ±10mA, then a +10V signal at the input will deliver +10mA at the output and +5V will deliver

+5mA etc.

Table of contents

Other Digitimer Analytical Instrument manuals

Digitimer

Digitimer DS7A User manual

Popular Analytical Instrument manuals by other brands

Cocraft

Cocraft NLT04 Original instructions

M&C

M&C GENTWO PMA1000 instruction manual

MICRO-EPSILON

MICRO-EPSILON optoncdt 1700 instruction manual

CONDTROL

CONDTROL XP4 PRO user manual

Extech Instruments

Extech Instruments BR200 user manual

Dewetron

Dewetron DEWE-30-16 Technical reference manual

EXTOL PREMIUM

EXTOL PREMIUM 8820043 Translation of the original user manual

RIDGID

RIDGID SeeSnake Compact quick start guide

Teledyne

Teledyne 3000PA operating instructions

YDLIDAR

YDLIDAR TIA user manual

Olympus

Olympus IPLEX FX Series instructions

Bosch

Bosch GLM 50 C Professional Original instructions

Reflecta

Reflecta DigiEndoscope instruction manual

Chinavision

Chinavision CVACZ-G696 Use manual

Fuji Electric

Fuji Electric ZKMA instruction manual

Teledyne

Teledyne 3300TA operating instructions

VOLTCRAFT

VOLTCRAFT IC-100HD operating instructions

RIDGID

RIDGID micro CA-25 Operator's manual