High Current Stimulus Isolator

Constant current stimulus isolator with 100 mA current range

• Constant current to 100 mA
• Unipolar or bipolar stimulation modes
• Built-in non-compliance alarm
• Input is optically isolated
• Standard TTL triggering
• DC test mode
• Powered by six rechargeable lead acid batteries
• 36V compliance
• Output polarity and output “on/off” switches

Options

Order code	Description	Battery Type	Includes Charger
A385RC	A385R with an A382 Battery Charger	Rechargeable Battery	Yes
SYS-A385R	High Current Isolator	Rechargeable Battery	No

Benefits

• 100 mA current capability
• Bipolar mode automatically generates alternating positive and negative pulses from TTL input
• Test mode simplifies performance verification
• Optical isolation enhances safety of the preparation and reduces noise susceptibility
• Battery charge status LEDs keep the experimenter informed of battery status
• Charger included at discounted price when system is purchases as A385RC

Applications

• Muscle electrophysiology
• In vivo/in vitro muscle stimulation

The A385 is an optically isolated current source, which can generate up to 100 mA of unipolar or biphasic constant current pulses or DC. Pulse duration is controlled manually or by an external 5V command. Output current amplitude is determined by a 3-digit 10-turn potentiometer. Maximum output voltage between the stimulating electrodes is +36V.

Delivers positive, negative or bipolar currents

For bipolar delivery, the polarity of the output can be toggled to the opposite polarity state with each successive pulse presented to the input. Pulse duration is controlled by an externally applied voltage. The in­put connector is a standard BNC, allowing TTL signals from a data acquisition system to be used.

Excellent accuracy and repeatability

The output amplitude is controlled by a 3-digit, ten-turn dial as a percentage of the range selected: for example, a setting of 45.6 in the 0-10 mA range trans­lates to 4.56 mA at the output. Ac­cu­ra­cy and repeat­abil­i­ty are ex­cel­lent. Designed for sub­cu­ta­ne­ous stim­u­la­tion, max­i­mum out­put volt­age at the stim­u­lat­ing elec­trodes is 36 volts, re­duc­ing the pos­si­bil­i­ty of ac­ci­den­tal tran­s­cu­ta­ne­ous shocks. A com­pli­ance/out­put alarm sounds when the 36V lim­it is reached. In­ter­nal cir­cuit­ry ensures elec­trodes are short-cir­cuit­ed dur­ing in­ac­tive pe­ri­ods (“elec­trode ex­haust­er” fea­ture). The A385 is not ap­pro­pri­ate for tran­scutane­ous stim­u­la­tion.

Rechargeable battery

The 1.2 amp-hour rat­ing of the six heavy-duty lead-acid re­charge­able batteries en­sures that all day ex­per­i­ments will not be in­ter­rupt­ed by dead bat­ter­ies when charged daily. Indicator lights and audible alarms keep the user constantly apprised of the battery charge status. The batteries are recharged by the A382 Sys­tem Charger, which is designed especially for the A385, and included with the A385RC. 

NOTE: Not intended for human use.

A385 Instruction Manual

OUTPUT WAVEFORM	DC or current pulse
OUTPUT CURRENT RANGES	1, 10, and 100 mA
CURRENT AMPLITUDE ERROR	0.5% of full scale, max.
CURRENT RESOLUTION REPEATABILITY	0.1% of full scale, typical
OUTPUT LOAD VOLTAGE EXCURSION (COMPLIANCE)	36 V
EXTERNAL COMMAND VOLTAGE   OUTPUT POLARITY   CURRENT RISE TIME AND DELAY   CURRENT FALL TIME AND DELAY   OUTPUT TO GROUND RESISTANCE   OPTOCOUPLER	5 V at 3 mA minimum, 8.5 V maximum Reversible, manual switch or electronically switched bipolar delivery 6 μs, typical (1 KΩ load) 10 μs, typical (1 KΩ load) 1012 Ω 2500 V, rated minimum breakdown voltage
POWER	Six rechargeable lead-acid batteries (Requires companion charger A382)
DIMENSIONS	8.5 x 3.5 x 5 in. (22 x 9 x 12 cm)
SHIPPING WEIGHT	5 lb. (2.3 kg)